# Concentric Semi-Circles _Posted on Sep 16, 2018_ +-- {.image} [[ConcentricSemiCircles.png:pic]] > The leftmost square has area $4$. What's the area of the square on the right? =-- * Thread [on twitter](https://twitter.com/Cshearer41/status/1041393416054206464) * [[concentric semi-circles techniques]] * [[concentric semi-circles solution]]