If two chords AB and CD of a circle AYDZBWCX intersect at right angles (see Fig.10.18), prove that arc CXA + arc DZB = arc AYD + arc BWC = semicircle.

Question

TextArc of a CircleNCERT Exemplar

Prove that the angle subtended by an arc at the center is double the angle subtended by it at any point on the remaining part of the circle.