Question

Prove this theorem: If quadrilateral is inscribed in a circle, then it's opposite angles are supplementary.​

Answer 1

Answer:

this is a cyclic quadrilateral

join GE

hence DF is equal to 90° (as 180)

next

join DF

hence GE is equal to 90°

The opposite angles in a cyclic quadrilateral are supplementary. i.e., the sum of the opposite angles is equal to 180˚.