Question

two concentric circles have a common centre o. The chord ab of the bigger circle touches the smaller circle at p. if op=3cm and ab=8cm, then find the radius of the bigger circle​

Answer 1

Answer:

Since AB is tangent to the smaller circle at P, he line OP is perpendicular to the line AB at P, so it bisects AB. The line OA is a radius of the larger circle.The triangle OAP is a right triangle with hypotenuse OA and legs OP = 3 and AP = 4 (half of AB).Using the Pythagorean Theorem, OA = sqrt(3^2 + 4^2) = 5 (note this is a 3:4:5 right triangle.