Question 290931
A chord that is 15 cm long is 20 cm from the centre of a circle.
 Find the length of the radius??
:
The 20 cm line bisects the chord, and you have a right triangle
r^2 = 7.5^2 + 20^2
r^2 = 56.25 + 400
r = {{{sqrt(456.25)}}}
r = 21.36 cm is the radius