The surface area of the pyramid is 180 in² to the nearest whole number.
Step 1: Calculate the area of the base.
The base of the pyramid is a rectangle with a length of 10 inches and a width of 10 inches. Therefore, the area of the base is:
Base area = length x width = 10 in x 10 in = 100 in²
Step 2: Calculate the area of each triangular face.
There are four triangular faces on the pyramid. Each triangle has a height of 4 inches and a base equal to the width of the base (10 inches). Therefore, the area of each triangular face is:
Triangle area = (1/2) * base * height = (1/2) * 10 in * 4 in = 20 in²
Step 3: Calculate the total surface area.
To find the total surface area, add the area of the base to the area of each triangular face:
Total surface area = Base area + 4 * Triangle area
Total surface area = 100 in² + 4 * 20 in²
Total surface area = 100 in² + 80 in²
Total surface area = 180 in²
Therefore, the surface area of the pyramid is 180 square inches to the nearest whole number.