how to find the length of the arc

Question

hi i dont get how to find the length of the arc can u please help me 

Answer 1

The important piece of information is the Circumference of the circle.

 

C = Πd      where d = diameter of the circle

C = 2Πr     where r = radius of the circle

 

It takes 360º for a complete circle.  The length of the arc is the Circumference.

 

For 180º, the length of the arc is C/2.

 

For 90º, the length of the arc is C/4.

 

So, how many degrees are used in the angle creating the arc?

      360º/Angle= C/length           [set up a proportion]

          To solve, cross-multiply.