Two tangents are drawn from an external point P to the circle with centre O which meet the circle at Q and R respectively. Which of the following is true?
∠QPO=∠OPR
Consider △PQO and △PRO
OP=OP (Common side)
OQ=OR (Radius of the circle)
∠PQO=∠PRO (Tangents are perpendicular to the radius at the point of contact)
So, △PQO≅△PRO (By RHS congruency criterion)
∴∠QPO=∠RPO (Corresponding sides of congruent triangles)