Semicircle stack
What is the total area enclosed by the three semicicles?
Problem
Image
![Semicircle Stack Semicircle Stack](/sites/default/files/styles/large/public/thumbnails/content-id-4881-2003-17.gif?itok=jiQdhyf4)
The diagram shows three semicircles, each of radius one.
What is the size of the total area shaded?
Student Solutions
Image
![Semicircle Stack Semicircle Stack](/sites/default/files/styles/large/public/thumbnails/content-id-4881-2003-17ans.gif?itok=epxBf35J)
(all of radius $1$).
Hence the total area is that of the rectangle
plus a circle of radius $1$ which equals $2 + \pi$