Answer:
<H = 40
Step-by-step explanation:
Complementary angles add to 90 degrees
2x+10 + x+20 = 90
Combine like terms
3x+30 = 90
Subtract 30
3x+30 -30 = 90-30
3x = 60
Divide by 3
3x/3 = 60/3
x = 20
<H = x+20 = 20+20 = 40