Question

A chord 30cm long is 20cm from the center of the circle. Calculate the length of the circle which is 24cm from the center

Answer 1

Draw a diagram. It should be easy to see that the radius is 25cm.

For this circle, no part of the circle is 24cm from the center.

However, a chord which is 24cm from the center subtends an angle θ such that cos(θ/2) = 24/25
The arc subtended by this angle is thus s = rθ = 25*2arccos(24/25) ≈ 14.19

Answer 2

8cm