The area of a trapezoid is given by the formula: A = 1/2(b1 + b2) * h.
In this case, the two bases of the trapezoid are 20 yards and 12 yards, and the height is 10 yards.
Plugging these values into the formula, we get:
A = 1/2(20 + 12) * 10
A = 1/2(32) * 10
A = 16 * 10
A = 160 square yards
Therefore, 160 square yards of rubber will be needed for the park.