Question

Need help pls on circle geometry

Answer 1

25

Explanation:

AB is a tangent to the circle hence the angle ABO is a right angle !!! With that knowledge we can construct a right-angled triangle with sides AB ,BO and OA .

Applying the Pythagorean theorem we get that OA is the hypotenuse and thus

`oa = \sqrt{ab {}^(2) + ob {}^(2) }`