Mathematics for IGCSE & O level - Circle Theorems (Section 2 - No. 47)
In a cyclic quadrilateral, if one of the angles is 70 degrees, what is the measure of the opposite angle?
70 degrees
90 degrees
110 degrees
140 degrees
Explication
Opposite angles of a cyclic quadrilateral are supplementary, so 180 - 70 = 110 degrees.