Answer:
80°, 40° and 60°
Step-by-step explanation:
Name the second angle X and the first angle to 2X (because it is twice the measure of angle number two) and the third angle to 20°+X (because it was 20° more than the second angle)
so we will have an equation of
180°=2x + x + (20°+x)
160°=4x
40°=x
so the second angle is 40° as it is represented by just one X
therefore the first angle which is twice the measure is 80° and the third angle which is 20° more is 60°. hope that helps!