Find angles in a right angle
A right angle is exactly 90掳. It is shown by a small square.
Angles that add together to make a right angle are called complementary angles.
If you know one complementary angle you can subtract it from 90掳 to find a missing angle.
Question
Calculate angle c.
A right angle is shown, so the two angles add up to 90掳.
c = 90掳 - 20掳
c = 70掳