Question

Can someone explain me the answer and how to solve it

Answer 1

The radius is 8.

Explanation:

Because OA is a radius and AB is a tangent, Angle A is a right angle. So you can use Pythagorean theorem (shortcut Pythagorean triple)

OA^2 + 15^2 = 17^2

OA^2 + 225 = 289

OA^2 = 64

OA = 8

OA is a radius, the radius = 8