Let C be a circle with a center O and a radius 5 cm. Let PQ be a tangent to the circle and A be the point of tangency. Let B be a point on PQ such that the length of AB is 12 cm. If the line joining O and B intersects the circle at R, find the length of BR (in cm).
Show answer & explanation
Correct answer: D
Explanation
The correct answer option 4 i.e. 8.
Given that
The radius of a circle (C) = 5 cm
AB = 12 cm
In a triangle OAB, OB2 = OA2 + AB2 = 25 + 144 = 169
OB = √169 = 13 cm
Radius OA = OR = 5 cm
BR = OB - OR = 13 - 5 = 8 cm