$\mathrm{O}$

$\mathrm{A}$

$\mathrm{B}$

$\mathrm{C}$

2

1

$\mathrm{A'}$

3

4

5

$2R$

$a$

6

7

\sin\mathit{A}=\sin\mathit{A'}

=\frac{\overline{\mathrm{BC}}}\overline{\mathrm{BA'}}

=\frac{a}{2R}

\therefore \  \frac{a}{\sin\mathit{A}}=2R

8

9

10

11

O = (7.042853704374549, -5.320029237335366)
A_1 = (-3.8322714685578583, 1.8644425963665745)
c = Circle(O, A_1)
A = Point(c)
B = Point(c)
C = Point(c)
다각형1, c_1, a, b = Polygon(A, B, C)
e = true
d = true
g = Ray(B, O)
A' = Intersect(c, g, 2)
다각형2, c_2, a', b_1 = Polygon(A', B, C)
h = true
α = Angle(A', C, B)
β = Angle(B, A, C)
γ = Angle(B, A', C)
f = true
i = true
k = 도구1(B, A')
p = 도구1(C, B)
j = true
l = true
m = true
n = true
o = true
q = true

Tool: 도구1
Input: D, E
Output: p

F = Midpoint(D, E)
G = Midpoint(D, F)
H = Midpoint(G, F)
k = Circle(F, H)
j = Segment(D, E)
l = OrthogonalLine(F, j)
I = Intersect(k, l, 2)
p = CircumcircleArc(D, I, E)