Question

Which equation must be true

Answer 1

Angle A + Angle B = 180.

Explanation:

This is because the shared angle is the diameter so because the circle theorem states that an angle from a diameter is 90º because it forms a right-angle triangle, then Angle A and B are both 90º so Angle A + Angle B = 180º.

Answer 2

angle A + angle B = 180

Explanation:

Inscribed angles onthe perimeter of a circle encompass twice as many degrees of arc as the angle measure ....

EACH of these angles encompass 180 degrees of arc

so EACH of these angles are 90 degrees

and the angles are equal