Answer:
875 square inches
Explanation:
The lateral area of a triangular prism is the sum of the areas of the three rectangular faces:
13×25 +15×25 +7×25 = (13 +15 +7)×25 = 35×25
= 875 . . . square inches
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The area of a rectangle is the product of its length and width. As we have seen here, the lateral area is the product of the height of the prism and the perimeter of its base.