負角關係
Author: 藍邦偉  老師

(1,0)

x

y

P(x,y)

θ

負角關係

P(x,y)=P(cosθ,sinθ)

sin(-θ)=-sinθ,cos(-θ)=cosθ

Q(x,-y)

-θ

O: 0.5 * (Corner[1.0] + Corner[3.0])
u = Vector((x(Corner[1.0]), y(O)), (x(Corner[3.0]), y(O)))
v = Vector((x(O), y(Corner[1.0])), (x(O), y(Corner[3.0])))
c = Circle(O, 3.0)
A = (3, 0)
θ = 3.6477381366681487 rad (slider from 0 to 6.283185307179586, step 0.017453292519943295)
P = Rotate(A, θ, O)
a = Segment(O, P)
A_1: 0.6 * O + 0.4 * A
B_1: 0.6 * O + 0.4 * P
d = CircleArc(O, A_1, B_1)
R: (x(P), 0.0)
b = Segment(P, R)
Q: (3.0 * cos(-(θ)), 3.0 * sin(-(θ)))
e = Segment(O, Q)
f = Segment(Q, R)
A_2: 0.2 * A + 0.8 * O
B_2: 0.2 * Q + 0.8 * O
g = CircleArc(O, B_2, A_2)
h = Segment(R, O)