In two concentric circles, a chord of length 8cm of the larger circle touches the smaller circle . If the radius of the larger circle is 5cm then find the radius of the smaller circle.

Answer 1

touches ---> tangent ?

the radius of the smaller circle is perpendicular to the midpoint of the larger chord

the radius of the larger circle is the hypotenuse , and half of the chord is the longer side

use Pythagoras to find the radius of the smaller circle

hint: the triangle is a Pythagorean triple (all sides are integers)