Question 782704
let the semi circle be at the width ends

width of rectangle = 15 yards
so radius of semicircle = 7.5 yards

semicircle on either side when you add up = one circle

perimeter of circle = 2 * pi * r

=2*pi*7.5

=15pi

add to this the lengths of the rectangle

20+20=40

Total fencing required = 40 + 15pi

=87.12  yards approx.