Question

AB is Tangent to circle O at B.

if AB = 7 and AO = 8.9, what is the length of radius r to the nearest tenth?

Answer 1

The radius equals 5.5

Answer 2

We are tasked to solve for the measurement of the radius of a circle with center O. The given values are the AB=7 units and AO=8.9 units. To further understand the problem, see attached picture. It is a right triangle, we can use Pythagorean theorem in solving for radius such as the solution is shown below:
AO² = r² + AB²
8.9² = r² + 7²
r² = 8.9² - 7²
r= 5.5

The radius is 5.5 units.