$\huge 切割、拼接$

$\huge %v份$

r

 π \,r

S= π \,r^2

$\huge 提示$

\bgcolor{#FFC0CB}{\ 圆的面积\ }

t = -1 (slider from -1 to 1, step 0.001)
r: 1
α = If(t ≟ -1, 45.0001°, t ≥ 0, 89.9999°, (45° * (t + 2)))
A: (0, 0)
B: A + (0, (r * tan(α)))
c = CircleArc(B, A, Rotate[A, ((2 * π) * r / Distance[B, A]), B])
n = 8 (slider from 4 to 40, step 2)
l1 = Sequence(Point[c, k], k, 0, 1, 1 / n)
c' = Dilate(c, 1 - 1 / tan(α), B)
l2 = Sequence(Point[c', k], k, 0, 1, 1 / ((2 * n)))
l3 = Sequence(CircleSector[l2((2 * k)), l1(k), l1(k + 1)], k, 1, n / 2)
l4 = Sequence(CircleSector[l2((2 * k)), l1(k), l1(k + 1)], k, n / 2 + 1, n)
C = Midpoint(l2(n), l1(n / 2 + 1))
t' = If(t < 0, 0, t)
l4' = Rotate(l4, (t' * 180°), C)
m = 0 (slider from 0 to 2, step 1)
a = Distance(Point[c', 0], c)

Tool: 简易坐标系
请选择原点，分别输入：x最小、最大值，y最小、最大值
Input: A, a, b, c, d
Output: B, C, O, u, v

$\huge\textcolor{}{x}$

$\huge\textcolor{}{y}$

$\Large\textcolor{}{O}$

A: (0, 0)
u = Vector(A + (a - 1, 0), A + (b + 1, 0))
v = Vector(A + (0, c - 1), A + (0, d + 1))
B: A + (b + 1, 0)
C: A + (0, d + 1)
O: A