Question

THEOREM
Prove that an isosceles trapezium is always cyclic.
OR If two nonparallel sides of a trapezium are equal, prove that it is
cyclic.



prove with figure...now..​

Answer 1

To prove that any given quadrilateral is cyclic, we need to prove that its opposite angles are supplementary (i.e. they add up to 180˚). We need to prove that ∠BAD + ∠BCD = 180 and ∠ADC + ∠ABC = 180˚. ... Since the opposite angles are supplementary, an isosceles trapezium is a cyclic quadrilateral.