What is the anwser?

Question

In ΔGHI,  GI is extended through point I to point J, m∠IGH=(x+16)  

m∠HIJ=(4x−12)∘ and  m∠GHI=(x+10)∘

Find m∠GHI.

Answer 1

In a triangle, the measure of an external angle (such as ∠HIJ) is equal to the sum of the non-adjacent interior angles. That means that:

m∠IGH + m∠GHI = m∠HIJ

x + 16 + x + 10 = 4x - 12

Solve for x. Once you have the value of x, m∠GHI = x + 10. The units are degrees.