The Area of a Circle
The geometrical shapes in Fig. 1 recently came into the Greenslade Collection. The semi‐triangular pieces of wood looked like slices from a pie, each 22.5° in angular width. They were tied together with a thin leather band tacked around their curved surfaces. What is this apparatus?
“The Area of a Circle”, The Physics Teacher, 49, 160 (2011)
The Physics Teacher