Answer:
Dimensions:
a = 630 yd
b = 210 yd
A = 132.300 yd²
Explanation:
Dimensions of rectangular pasture
a and b and a = 3*b a is opposite side at the river, therefore
Area of rectangular pasture
A = a * b and perimeter of rectangular area ( with fencing material ) is
P = a + 2b or P = 3*b + 2*b ⇒ 1050 = 5*b
b = 1050 / 5 ⇒ b = 210 yd
And as a = 3*b ⇒ a = 3*210 ⇒ a = 630 yd
And the area is A = 630*210 = 132.300 yd²