SOLUTION: What is the ratio of sum of interior angles of a triangle to its exterior angles

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Question 1054682: What is the ratio of sum of interior angles of a triangle to its exterior angles
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Let the interior angles be A, B, and C and a,b, and c be the exterior angles.
A%2BB%2BC=180
A%2Ba=180
B%2Bb=180
C%2Bc=180
A=180-a
B=180-b
C=180-c
Substituting,
180-a%2B180-b%2B180-c=180
a%2Bb%2Bc=360
So then,
R=%28A%2BB%2BC%29%2F%28a%2Bb%2Bc%29=180%2F360=1%2F2