How can you prove that angle o is equal to twice angle a

How can you prove that angle o is equal to twice angle a

Make the bisector of big angle o

What is a ^ 1 + A ^ 2 + A ^ 3 +.. + A ^ n
RTRT

S = a ^ 1 + A ^ 2 + A ^ 3 +.. + A ^ n as = a ^ 2 + A ^ 3 +.. + A ^ n + A ^ (n + 1) subtracting (1-A) s = A-A ^ (n + 1) s = [A-A ^ (n + 1)] / (1-A)

A to 1 / 2 is equal to B to 1 / 3

a: 1 / 2 = B: 1 / 3
Product of internal terms = product of external terms
So:
2 / b = 3 / A
a: B = 1 / 2:1 / 3 = 3:2

Three A's + two A's + one a's equal to 615 A's equal to several a's

3A+2A+A=615
6A=615
A=615/6 =102.5