Question

Segment MP is tangent to circle O. Find the length of the radius of circle O.

Answer 1

R = 10.5

Explanation:

Using Pythagorean theorem, we can write

(OM)^2 + 10^2 = (OR + 4)^2

Since OM = OR, let's call this segment R for brevity.

R^2 + 10^2 = (R + 4)^2

R^2 + 100 = R^2 + 8R + 16

This simplifies to

8R = 84

or R = 10.5