Answer with explanation:
Circumference of circle =2 π r, where r is radius of circle.
If total length , that is thread or any wire used for constructing this circle is l, then
l=2 π r
If, length of circle =1 unit

If central angle is given=Ф , then
⇒Length of segment=Radius of circle(r) × Central Angle (Ф), where Ф, is in radians.
