Mathematics
In the figure (ii) given below, O is the center of a circle. If AB and AC are chords of the circle such that AB = AC and OP ⊥ AB, OQ ⊥ AC, prove that PB = QC.

Related Questions
In an equilateral triangle, prove that the centroid and the circumcentre of the triangle coincide.
In the figure (i) given below, OD is perpendicular to the chord AB of a circle whose center is O. If BC is a diameter, show that CA = 2OD.

In the figure (i) given below, a line l intersects two concentric circles at the points A, B, C and D. Prove that AB = CD.

In the figure (ii) given below, chords AB and CD of a circle with centre O intersect at E. If OE bisects ∠AED, prove that AB = CD.
