Question

the area enclosed by two concentric circles is 330sq.cm.if the radius of the smaller circle is 8cm then find the radius of the bigger circle​

Answer 1

Answer:

Example

Call the radius of the inner circle x. The radius makes a perpendicular (90°) with the chord since it is tangent to the circle. Therefore you have a hypotenuse of 8 cm one leg of 1/2 of 4 or 2 cm and the other leg of unknown “x”. thus, x^2 + 2^2 = 8^2 or x^2 + 4 = 64. If that is true then x^2 = 60 and x = 60^(1/2) or square root of 60 or the square root of 4x3x5 or 2 x 15^(1/2) would be the radius of the smaller circle