Circumference & area
Unroll the circle to get 2πr. Arrange equal sectors into a near-rectangle with base πr and height r.
units
Circumference
C = 2πr
= 25.13
Area
S = πr²
= 50.27
Circumference: one full roll = 2πr. Area: sectors form a near-rectangle → S = πr × r = πr².