Question

Complement of 1/2 of a right angle

Answer 1

Complementary angles are those whose sum is 90°, and 1/2 of a right angle is 45° (1/2 × 90) so the complement of 45° = 90 - 45 = 45°.

Instead of solving it you can also think of it as half of 90° will need another half to make 90° again so two 45° angles are needed.