# Sine Formula for the Area of a Triangle The **sine formula for the area of a triangle** is a formula that calculates the area of a triangle from two of the sides and the angle between them. Given a triangle as follows: +-- {.figure} [[StandardTriangle.png:pic]] =-- the area of this triangle is given by any of the following formulae: $$ \Area = \frac{1}{2} a b \sin C = \frac{1}{2} b c \sin A = \frac{1}{2} c a \sin B $$ This can be used to deduce the [[sine rule]].