Jesse found a set of new erasers that are shaped like right angled triangular prisms, which is his favorite three-dimensional shape. After some quick measurements, he has figured out that the sides of the triangle on each end of the eraser have a base of 4 inches, a height of 3 inches, and a hypotenuse of 5 inches. Furthermore, the eraser is 6.25 inches long. Using a net, figure out the total surface area of the eraser. (1 point)

____in.2

1 answer

To find the total surface area of the eraser, we need to calculate the area of each of the five faces and then sum them up.

1. The two triangular faces:
Each triangular face has an area of (1/2) * base * height
= (1/2) * 4 * 3
= 6 in^2
Since there are two triangular faces, the total area of both is 2 * 6 = 12 in^2

2. The three rectangular faces:
Each rectangular face has an area of base * height
= 4 * 6.25
= 25 in^2
Since there are three rectangular faces, the total area of all three is 3 * 25 = 75 in^2

Now, summing up the areas of all five faces:
12 + 75 = 87 in^2

Therefore, the total surface area of the eraser is 87 square inches.