Answer:
9/20
Step-by-step explanation:
Not hard. Multiply top and bottom by the other number. 3*3 = 9, and 4*5 = 20. so 9/20
What is the expression though?
Circumference = 2 pi r = 20 pi
corresponding to 360 degrees
so an arc of 4pi feet will have a degree measure of 5pi / 20pi * 360 = 1/4 * 360 = 90 degrees