Why is Area = πr²?
Slice the circle → stand the slices in a row → read off
πr × r
Rearrange ▶
Reset
scrub
slices
8
slices
8
of 360°/8 = 45° each
strip width (half the rim)
πr
, never changes
top-edge bumpiness
7.6
% of r
so the area is
πr × r =
πr²