Notes
Catriona Agg's puzzles

Catriona Agg’s Geometry Puzzles

Catriona Agg’s Puzzles from 2025

three congruent rectangles vi July 5, 2025
four quarter circles iii June 28, 2005
two triangles in a semi-circle June 21, 2025
four squares x June 14, 2025
four squares ix June 7, 2025
three regular hexagons and a semi-circle May 31, 2025
four quarter circles ii May 30, 2025
subdivided triangle ii May 29, 2025

Catriona Agg’s Puzzles from 2023

four squares and an isosceles triangle Aug 13, 2023
two triangles and a quarter circle Aug 12, 2023
two squares and a quarter circle Aug 11, 2023
five squares ii Apr 14, 2023
four rectangles and a hexagon Mar 12, 2023
two quarter circles and a circle Feb 25, 2023
subdivided hexagon iv Feb 17, 2023
a semi-circle and a quarter circle in a rectangle Feb 16, 2023
three squares viii Feb 15, 2023
three lengths in a semi-circle Feb 14, 2023
three squares vii Jan 7, 2023

Catriona Agg’s Puzzles from 2022

subdivided semi-circle Oct 26, 2022
three squares vi Oct 24, 2022
four squares and a triangle ii Aug 26, 2022
five equilateral triangles ii Aug 23, 2022
three semi-circles in a rectangle Aug 19, 2022
a circle in a rectangle Aug 17, 2022
two squares iii Aug 16, 2022
six rectangles Apr 19, 2022
four houses in a semi-circle Apr 14, 2022
two triangles in a square Apr 12, 2022
subdivided hexagon iii Apr 4, 2022
three squares and two triangles Mar 16, 2022
a quarter circle and a semi-circle in a triangle Feb 22, 2022
four squares and a triangle Feb 20, 2022
two equilateral triangles iii Feb 19, 2022
two squares ii Feb 18, 2022
three squares and a triangle Feb 17, 2022
two quarter circles Feb 16, 2022
a square and a triangle Feb 14, 2022

Catriona Agg’s Puzzles from 2021

a square in a square Dec 20, 2021
two rectangles Nov 10, 2021
subdivided triangle iii Oct 23, 2021
three squares v Sep 4, 2021
two semi-circles in an equilateral triangle Aug 11, 2021
three regular hexagons iv Aug 10, 2021
five regular polygons Aug 8, 2021
three squares and a rectangle Jul 30, 2021
three quarter circles ii Jul 29, 2021
two equilateral triangles ii Jul 28, 2021
two semi-circles and two quarter circles Jul 26, 2021
five squares Jul 25, 2021
five rectangles in a semi-circle Jul 23, 2021
two squares and an equilateral triangle ii Jul 18, 2021
two rectangles and a square ii Jul 18, 2021
subdivided hexagon ii Jul 15, 2021
four congruent triangles Jul 11, 2021
two circles Jul 3, 2021
three congruent rectangles v May 23, 2021
two rectangles and a square May 16, 2021
three squares ii May 2, 2021
two overlapping triangles ii Apr 11, 2021
two regular hexagons iii Apr 10, 2021
isosceles and equilateral triangles Apr 10, 2021
two concentric circles Apr 10, 2021
four squares and a quarter circle Apr 9, 2021
hexagon and a square Apr 6, 2021
two quarter circles in a rectangle Apr 5, 2021
four squares in a semi-circle Apr 4, 2021
triangle in two tilted squares Apr 3, 2021
quarter circle overlapping a circle Apr 2, 2021
five equilateral triangles Apr 1, 2021
four equilateral triangles inside a hexagon Mar 31, 2021
two quarter circles in a semi-circle ii Mar 30, 2021
three squares iii Mar 29, 2021
four squares viii Mar 28, 2021
seven quarter circles inside a semi-circle Mar 27, 2021
two hexagons and a triangle Mar 26, 2021
two squares inside a semi-circle Mar 23, 2021
five semi-circles Mar 22, 2021
four squares vii Mar 21, 2021
four parallel semi-circles Mar 20, 2021
three overlapping hexagons Mar 19, 2021
four squares vi Mar 18, 2021
two squares on a hexagon Mar 17, 2021
semi-circles in a rectangle Mar 16, 2021
three triangles in a hexagon Mar 15, 2021
striped semi-circle Mar 14, 2021
two quarter circles and a semi-circle ii Mar 13, 2021
five quarter circles Mar 12, 2021
subdivided hexagon Mar 10, 2021
multiple semi-circles iii Mar 7, 2021
three overlapping semi-circles Mar 6, 2021
three quarter circles Mar 2, 2021
two squares on a diameter of a circle Mar 1, 2021
a hexagon and a nonagon Feb 28, 2021
four quarter circles in a circle Feb 27, 2021
three regular hexagons iii Feb 26, 2021
two squares overlapping a square ii Feb 23, 2021
three congruent triangles ii Feb 21, 2021
two triangles overlapping a quarter circle Feb 20, 2021
three congruent rectangles iv Feb 19, 2021
three congruent triangles in a semi-circle Feb 18, 2021
triangle over a circle Feb 17, 2021
multiple semi-circles iv Feb 16, 2021
four squares v Feb 15, 2021
two squares overlapping a square Feb 14, 2021
zig-zag inside a square Feb 13, 2021
two semi-circles in a semi-circle Feb 11, 2021
six triangles in a hexagon Feb 9, 2021
two overlapping triangles Feb 7, 2021
four squares inside a rectangle Jan 31, 2021
two triangles in a circle and semi-circle Jan 30, 2021
triangle in a rectangle Jan 29, 2021
multiple semi-circles ii Jan 27, 2021
square overlapping a square and a rectangle Jan 24, 2021
chord splitting a square in half Jan 23, 2021
rectangle tilted over a square Jan 16, 2021
multiple angles Jan 10, 2021
three circles and two semi-circles in a circle Jan 9, 2021

Catriona Agg’s Puzzles from 2020

four triangles in a square Dec 31, 2020
zig-zag inside a rectangle Dec 30, 2020
five squares across a square Dec 23, 2020
two squares and a semi-circle Dec 13, 2020
two circles in a square ii Oct 31, 2020
triangles formed from rectangles Oct 29, 2020
three triangles in a circle in a triangle Oct 24, 2020
two quarter circles in a semi-circle Aug 31, 2020
circle inside a triangle Aug 28, 2020
similar rectangles Aug 26, 2020
two semi-circles in a circle Aug 21, 2020
semi-circle and quarter circle in a square Aug 17, 2020
multiple semi-circles in a circle Aug 15, 2020
four squares iv Aug 14, 2020
triangle over two rectangles Aug 7, 2020
subdivided decagon Jul 30, 2020
two congruent rectangles and a semi-circle Jul 29, 2020
a rectangle in a square Jul 26, 2020
two half-squares and a circle Jul 25, 2020
three congruent rectangles iii Jul 23, 2020
Squares and a Semi-Circle Jul 22, 2020
semi-circle in a square in a quarter circle Jul 19, 2020
two triangles and three concentric semi-circles Jul 18, 2020
five congruent rectangles Jul 15, 2020
three squares iv Jul 12, 202
five rectangles tiling a square Jul 11, 2020
rectangle overlapping a circle Jul 5, 2020
swirling semi-circles Jun 14, 2020
hexagon in a quarter circle May 31, 2020
six semi-circles inside a hexagon May 30, 2020
four quarter circles May 29, 2020
two overlapping triangles and a circle May 28, 2020
two squares diagonally inside a rectangle May 26, 2020
two circles and two semi-circles May 25, 2020
two tilted squares May 23, 2020
a circle and two semi-circles in two hexagons May 14, 2020
four squares overlapping a rectangle May 9, 2020
two semi-circles and a triangle May 8, 2020
a square and a hexagon May 5, 2020
five circles in a square May 2, 2020
two quarter circles in a rectangle in a semi-circle Apr 30, 2020
four squares iii Apr 28, 2020
four squares ii Apr 26, 2020
two circles inside an equilateral triangle Apr 25, 2020
three congruent rectangles ii Apr 24, 2020
four congruent squares inside a larger square Apr 23, 2020
two semi-circles and an equilateral triangle Apr 22, 2020
two quarter circles and a semi-circle Apr 21, 2020
three stacked squares Apr 19, 2020
two circles in a square Apr 18, 2020
three overlapping rectangles ii Apr 17, 2020
semi-circle splitting a triangle Apr 16, 2020
two semi-circles diagonally across a square Apr 15, 2020
two neighbouring rectangles Apr 13, 2020
two overlapping semi-circles Apr 12, 2020
nested semi-circles Apr 11, 2020
two circles in a triangle ii Apr 10, 2020
tangential hexagon and circle Apr 9, 2020
three overlapping rectangles Apr 8, 2020
three circles forming a triangle Apr 7, 2020
four squares in a circle Apr 6, 2020
three equal area rectangles Apr 5, 2020
six equal area rectangles Apr 4, 2020
angle formed by three squares Apr 2, 2020
quadrilateral splitting a semi-circle Apr 1, 2020
two regular hexagons ii Mar 28, 2020
three squares in a circle ii Mar 21, 2020
rectangle across a rectangle Mar 16, 2020
two squares and an equilateral triangle Mar 14, 2020
quarter circles in a rectangle in a circle Mar 7, 2020
nested isosceles triangles Mar 5, 2020
five circles in a rectangle in a semi-circle Feb 29, 2020
two semi-circles inside a rectangle Feb 23, 2020
two squares inside an equilateral triangle Feb 22, 2020
tilted rectangle in a square Feb 20, 2020
circle in a quarter circle Feb 18, 2020
three semi-circles Feb 16, 2020
a square and a rectangle overlapping Feb 14, 2020
three circles in a hexagon in a circle Feb 10, 2020
three circles Feb 8, 2020
three squares in a triangle Feb 4, 2020
four squares Feb 1, 2020
arcs in a semi-circle Jan 30, 2020
three isoscelese triangles inside a triangle Jan 23, 2020
square and rectangle overlapping in a semi-circle Jan 16, 2020
three stacked squares and a fourth square Jan 12, 2020
parallelogram area Jan 7, 2020
three squares Jan 4, 2020
parallelogram in a rectangle Jan 1, 2020

Catriona Agg’s Geometry Puzzles from 2019

three circles in a rectangle Dec 31, 2019
two semi-circles inside a semi-circle Dec 29, 2019
two squares Dec 28, 2019
three squares and an equilateral triangle Dec 26, 2019
pentagram in a circle Dec 24, 2019
rectangle quartered by semi-circles Dec 23, 2019
chord dividing a triangle into two Dec 22, 2019
two pentagons Dec 20, 2019
two circles in a rectangle Dec 17, 2019
angle formed by three rectangles Dec 14, 2019
two rectangles in a square Dec 12, 2019
five semi-circles around a rectangle Dec 11, 2019
three equal angles in a rectangle Dec 7, 2019
a square, a circle, and a rectangle Dec 4, 2019
three right-angled triangles Nov 30, 2019
two rectangles overlapping a square Nov 24, 2019
areas in a crossed trapezium Nov 20, 2019
seven hexagons Nov 18, 2019
a pattern of squares Nov 17, 2019
three hexagons and a rectangle Nov 15, 2019
six circles inside a circle inside a square Nov 9, 2019
stacked squares inside two squares Nov 7, 2019
three squares inside a triangle Oct 30, 2019
three congruent triangles Oct 29, 2019
two semi-circles inside a semi-circle ii Oct 27, 2019
multiple semi-circles Oct 25, 2019
two congruent rectangles in a square Oct 24, 2019
three circles in a rectangle ii Oct 19, 2019
overlapping triangles in a circle Oct 13, 2019
diagonal in a square Oct 11, 2019
seven circles Oct 5, 2019
angles in two hexagons Sep 28, 2019
three overlapping squares Sep 19, 2019
four squares and a semi-circle Sep 7, 2019
two overlapping hexagons and a rectangle Sep 2, 2019
two rectangles of equal area Aug 31, 2019
three squares overlapping a semi-circle Aug 29, 2019
two hexagons and a square Aug 28, 2019
four hexagons Aug 26, 2019
two squares in a semi-circle Aug 24, 2019
three squares in a semi-circle Aug 23, 2019
three congruent squares overlapping a square Aug 22, 2019
three triangles in a square Aug 20, 2019
trisected hexagon Aug 19, 2019
two congruent quadrilaterals and a rectangle Aug 16, 2019
semi-circle in a square ii Aug 14, 2019
circle in pentagon in semi-circle Aug 11, 2019
rectangles in concentric rings Aug 9, 2019
three regular hexagons ii Aug 8, 2019
one rectangle inside another with semi-circles Aug 5, 2019
two rectangles and a semi-circle Aug 3, 2019
three equilateral triangles and a semi-circle Aug 2, 2019
three circles in a semi-circle Aug 1, 2019
upside-down semi-circles in a semi-circle Jul 30, 2019
stacked triangles Jul 29, 2019
triangles in a dodecagon Jul 27, 2019
angle formed by two squares ii Jul 26, 2019
three parallel semi-circles Jul 24, 2019
semi-circle in a right-angled triangle Jul 23, 2019
three congruent squares in a rectangle Jul 22, 2019
three hexagons in a trapezium Jul 20, 2019
regular hexagon and rectangle Jul 12, 2019
stack of congruent rectangles Jun 28, 2019
angles in a circle Jun 27, 2019
striped dodecagon Jun 24, 2019
two squares overlapping a third square Jun 15, 2019
three squares and a semi-circle Jun 7, 2019
three congruent rectangles Jun 4, 2019
rectangle, circle, and triangle Jun 1, 2019
two regular hexagons May 30, 2019
angle in a circle and semi-circle May 28, 2019
circle and two squares May 26, 2019
divided hexagon May 25, 2019
two overlapping squares May 20, 2019
two squares in a triangle May 19, 2019
a semi-circle and quarter circle in a square May 17, 2019
overlapping triangle and hexagon May 14, 2019
overlapping triangle and rectangle May 10, 2019
divided hexagon ii May 8, 2019
semi-circle between two quarter circles May 6, 2019
two squares and two equilateral triangles iii May 5, 2019
two squares and two equilateral triangles ii May 5, 2019
angles in two circles May 3, 2019
square with midpoints May 1, 2019
angle formed by two squares Apr 28, 2019
two circles inside two polygons inside a circle Apr 26, 2019
quartered hexagon Apr 24, 2019
two semi-circles in a square Apr 22, 2019
three semi-circles around a triangle Apr 20, 2019
two overlapping squares ii Apr 18, 2019
two rectangles with diagonals Apr 17, 2019
two semi-circles and a rectangle Apr 16, 2019
semi-circle on a hexagon Apr 14, 2019
divided square Apr 12, 2019
three adjacent triangles Apr 10, 2019
triangle and circle inside square Apr 7, 2019
two squares on a triangle Apr 4, 2019
square, rectangle, and two semi-circles Apr 3, 2019
three triangles and a rectangle inside a circle Mar 30, 2019
triangle inside a square Mar 26, 2019
triangle inside circle and triangle Mar 20, 2019
circle in triangle in square Mar 17, 2019
quarter circles in a square in a circle Mar 16, 2019
triangle overlapping a hexagon Mar 13, 2019
two circles in a triangle Mar 10, 2019
inverse star in a rectangle Mar 7, 2019
three overlapping circles Mar 3, 2019
three tilted rectangles Mar 1, 2019
overlapping hexagons Feb 26, 2019
square overlapping a quarter circle Feb 24, 2019
two hexagons in a rectangle Feb 23, 2019
semi-circle in a circle Feb 22, 2019
two triangles overlapping a rectangle Feb 21, 2019
square on an octagon Feb 19, 2019
circle and semi-circle in triangle Feb 18, 2019
overlapping triangles Feb 16, 2019
tilted rectangles Feb 13, 2019
triangle in semi-circle with square Feb 11, 2019
circles in overlapping triangles Feb 7, 2019
tilted triangles Feb 2, 2019
two quarter circles in a square Jan 28, 2019
two squares and a rectangle in an octagon Jan 26, 2019
square overlapping a circle Jan 25, 2019
six semi-circles in a circle Jan 21, 2019
rectangle on a hexagon Jan 19, 2019
two squares on a circle Jan 16, 2019
pentagon with two semi-circles Jan 14, 2019
striped hexagon Jan 13, 2019
circle in a hexagon in a semi-circle Jan 11, 2019
overlapping rectangle and semi-circle Jan 5, 2019

Catriona Agg’s Geometry Puzzles from 2018

two rectangles in a semi-circle Dec 31, 2018
divided hexagon iii Dec 30, 2018
circles around a triangle Dec 16, 2018
rectangles stacked in a semi-circle Dec 12, 2018
two circles, two squares Dec 11, 2018
subdivided square Dec 5, 2018
chords dividing a triangle into five Dec 3, 2018
three rectangles as a triangle Dec 1, 2018
partitioned square Nov 28, 2018
two squares overlapping a semi-circle Nov 26, 2018
five triangles in a rectangle Nov 25, 2018
nested circles and a triangle Nov 24, 2018
square in a triangle in a square Nov 23, 2018
quarter circles in a rectangle Nov 22, 2018
semi-circles in a quarter circle Nov 21, 2018
three squares on a line Nov 19, 2018
nested circles and polygons Nov 18, 2018
semi-circle and tangents in a square Nov 17, 2018
equilateral triangle in a hexagon Nov 17, 2018
three regular hexagons Nov 14, 2018
triangles in a semi-circle Nov 13, 2018
equilateral triangles in a square Nov 12, 2018
three aligned triangles Nov 11, 2018
crossed hexagon Nov 10, 2018
square in a semi-circle in a square Nov 8, 2018
two equilateral triangles in a semi-circle Nov 7, 2018
three squares in a circle Nov 5, 2018
square in a circle in a quarter circle in a square Nov 4, 2018
triangle in a circle in a quarter circle in a square Nov 4, 2018
arcs inside a triangle Nov 2, 2018
quadrilateral from two squares in a square Oct 30, 2018
triangle centres and square corners Oct 29, 2018
hexagon and concentric circles Oct 28, 2018
chord and annulus Oct 27, 2018
dissected hexagon Oct 26, 2018
circles in rhombii sequal Oct 26, 2018
circles in triangle and rhombus Oct 25, 2018
circles resting on triangles Oct 24, 2018
arbelos Oct 23, 2018
four circles in a triangle in a circle Oct 22, 2018
triangles with a parallelogram Oct 21, 2018
three squares in a square Oct 18, 2018
two circles in an equilateral triangle Oct 17, 2018
semi-circles in a square Oct 15, 2018
five rectangles in a square Oct 14, 2018
five overlapping circles Oct 11, 2018
four regular polygons Oct 8, 2018
four squares around a quadrilateral Oct 7, 2018
two perpendicular equilateral triangles Oct 6, 2018
nested circles and polygons ii Oct 5, 2018
spiralling semi-circles Oct 3, 2018
five decreasing squares Oct 1, 2018
triangle and semi-circle in a circle Sep 29, 2018
subdivided parallelogram Sep 27, 2018
triangle in four rectangles Sep 26, 2018
circle in a trapezium Sep 24, 2018
subdivided triangle Sep 19, 2018
two circles inside a square Sep 17, 2018
concentric semi-circles Sep 16, 2018
shaded spikes in a hexagon Sep 14, 2018
squares in an octagon Sep 11, 2018
four squares in a big square Sep 9, 2018
stacked boxes in circles in squares Sep 8, 2018
four stacked squares in a circle in a square Sep 8, 2018
overlapping square and circle Sep 6, 2018
two circles inscribed in triangles in a semi-circle Sep 3, 2018
arcs in a circle Sep 1, 2018
six squares in a hexagon Aug 31, 2018
four equilateral triangles round a square Aug 30, 2018
two triangles in a rectangle Aug 29, 2018
two overlapping squares iii Aug 28, 2018
two isosceles triangles Aug 28, 2018
four isosceles triangles in a circle Aug 26, 2018
two octagons and two squares Aug 25, 2018
hexagon in a star in a hexagon Aug 24, 2018
stacked hexagons Aug 23, 2018
a square, triangle, and circle in a square Aug 22, 2018
region of an octagon Aug 21, 2018
semi-circle in a square Aug 20, 2018
polygons with equal perimeter Aug 19, 2018
stacked shapes Aug 19, 2018
four squares overlapping a circle Aug 17, 2018
triangle in circle in triangle in semi-circle Aug 15, 2018
bell-ringing braids Aug 14, 2018
four equilateral triangles Aug 13, 2018
three squares and two equilateral triangles Aug 13, 2018
zig-zag triangles Aug 12, 2018
squares meeting in a circle Aug 12, 2018
four aligned squares Aug 10, 2018
three aligned squares Aug 9, 2018
lengths in a crossed trapezium Aug 9, 2018
overlapping squares Aug 8, 2018
toppled square Aug 7, 2018
two rectangles overlapping a circle Aug 2, 2018
subdivided circles May 21, 2018

Revised on November 5, 2025 22:35:53 by Andrew Stacey?