algebra
posted by Anonymous on .
In triangle ABC, the size of angle B is 5 times the size of angle A, and the size of Angle c is 15 degrees less than 4 times the size of angle A. What is the size of angle A? What is the size of angle B? What is the size of angle C?

A+B+C = 180 for a triangle ABC
B = 5A
C = 4A15
A + 5A + 4A  15 = 180
10A = 195
A = 19.5
B = 97.5
C = 63