Find the value of x. Show all calculations and an explanation as to whether or not your answer is reasonable. Leave your answer in simplest radical form.

Question

Find the value of x. Show all calculations and an explanation as to whether or not your answer is reasonable. Leave your answer in simplest radical form.

Answer 1

Here's the circle theorem that you need to solve this problem:

If a tangent and secant to a circle intersect at an outside point, the square of the measure of the tangent equals the product of the secant and its external segment.

Thus x² = 8·4. I'll let you solve for x.