Answer: We can use the formula for the area of a triangle:
Area = (1/2) * base * height
where the base is the length of the side of the triangle that is perpendicular to the height. We can rearrange this formula to solve for the base:
base = (2 * Area) / height
Plugging in the values given in the problem, we get:
base = (2 * 120 square yards) / 12 yards
base = 20 yards
Therefore, the length of the base of the triangle is 20 yards.
Explanation: