The radius of a circle is 8 feet. What is the length of a 135° arc?

Answer 1

Remember that circumference (C) is calculated from C = 2•π•r but in this case you only want to go part way around the circle. How far? 135°/360° or 3/8 of the way around the circle. So the arc length (AL) = (3/8)•2•π•r

AL = (3/8)(2)(π)(8) feet (I'll let you do the multiplication)

Answer 2

6π

2π*8*(135/360)

Answer 3

convert 135 to radians 135 degrees = 135pi/180 radians

arc length = radius times radians = 8 x 135pi/180 feet

= about 18.8 feet

circumference of a circle is 2pir = 16pi = about 50 feet

for 135 degrees, the arc length is 135/360 x 50 = about 18.8

arc length is just part of the circumference, in this example a fraction of it = 135/360 = 3/8 of the circumference 3/8 x 16pi = 6pi = about 18.8 feet