Question

Point c is the center of the circle. what is the measure of arc ab if angle acb is equal to 80 degrees

Answer 1

$80 \times \pi \div 180 \times radius$

Answer 2

According the above information, point C is the center of the circle.  

We need to calculate the measure of arc ab if the angle abc is equal to the central angle.

It is essential to know that the C is a center of the circle, and then ACB is a central angle for arc AB.

Hence the arc AB is equal to angle ACB which is 56 degrees.