What is the area of a triangular lawn with a base of 80 feet and an altitude of 70 feet?

To find the area of a triangular lawn, you can use the formula for the area of a triangle, which is given by:

Area = 1/2 × base × height.

In this problem, the base of the triangle is 80 feet and the altitude (height) is 70 feet. Plugging these values into the formula:

Area = 1/2 × 80 feet × 70 feet

Calculating this step-by-step:

1. First, multiply the base and the height: 80 × 70 = 5600.

2. Next, multiply this result by 1/2: 1/2 × 5600 = 2800.

Thus, the area of the triangular lawn is 2800 square feet. This confirms that the correct choice is indeed the option that represents 2800 square feet, reflecting the proper application of the area formula for a triangle.