In circle O, AE and FC are diameters. Arc ED measures 17°. What is the measure of EFC?

Solution:

ED = S(length of arc) = rθ

θ = 17° = 0.2968 radians

Therefore

Arc ED = 0.2968 × OC

= 0.2968 × r

ARC EFC = rθ, where θ = 270° - 17° = 253°

In radians 253° = (22/7)(253/180) = 4.4175

ARC EFC = 4.4175 × r

Where r is the radius of the circle

In circle O, AE and FC are diameters. Arc ED measures 17°. What is the measure of EFC?

Solution:

The measure of EFC is 4.4175r