SOLUTION: If the measures of the angles of a triangle are in the ratio of 3:5:7, what is the measure of the largest angle of the triangle? A) 60 B) 72 C) 84 D) 90 E) 144 Please exp

Algebra ->  Triangles -> SOLUTION: If the measures of the angles of a triangle are in the ratio of 3:5:7, what is the measure of the largest angle of the triangle? A) 60 B) 72 C) 84 D) 90 E) 144 Please exp      Log On


   

Question 474904: If the measures of the angles of a triangle are in the ratio of 3:5:7, what is the measure of the largest angle of the triangle?
A) 60
B) 72
C) 84
D) 90
E) 144
Please explain how I could approach and solve this, thanks!
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Let the angles be 3x, 5x, 7x. Their sum is 180, so

3x + 5x + 7x = 180

15x = 180 --> x = 12

The largest angle is 7x, which is 7(12) = 84, choice C.