Answer:
I. Evaluate the largest angle when x = 15
Step-by-step explanation:
First, solve for x:
x + 8x + x + 30 = 180
10x = 180 - 30
10x = 150
x = 15
Here in the question, his friend wants to find the largest angle in triangle.
So, input x = 15 in the largest angle.
Which is, 8x = 8(15) = 120° <--- largest angle in the triangle.