Circumference
Area
π & Rationals
Radius
5
Zoom
70%
r
Radius
d
Diameter
C
Circumference
Unwrap C
Perceive τ
Perceive π
C = τr
= 2πr
= πd
d = 2r
·
τ = 2π
Triangles
24
One Circle
Two Circles
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0%
Join
0%
Unroll & Join
Perceive It
Zoom
×1
π = 3.141592653589793…
Drag the number line. Zoom to reveal finer exact ratios.
Area
A = πr²