Answer:
x = 11
m<H = 39°
Step-by-step explanation:
m<G = 6x - 15
m<H = 3x + 6
complementary angles = angles that add up to 90
6x - 15 + 3x + 6 = 90
9x = 99
m<H = 3x + 6, plug in 11 as x
3 * 11 + 6
= 33 + 6