Answer:
c = 11.3 yards
Step-by-step explanation:
The area (A) of a trapezium is calculated as
A = [tex]\frac{1}{2}[/tex] h (a + b)
where h is the perpendicular height and a, b the parallel bases
Here A = 416.955, h = 20.9, a = 28.6 and b = c, thus
[tex]\frac{1}{2}[/tex] × 20.9 × (28.6 + c) = 416.955, that is
10.45(28.6 + c) = 416.955 ( divide both sides by 10.45 )
28.6 + c = 39.9 ( subtract 28.6 from both sides )
c = 11.3 yards
