The amount of plywood that he needs to buy will be 21 square feet.
What is the surface area of the triangular prism?
Let the prism with a length of L of the rectangular surface.
And the dimension of the triangle is A, B, and C. Then we have
SA = 2(area of triangle) + 3(area of rectangle surface)
A triangular prism.
The rectangular sides are 3 feet by 2 feet, 3 feet by 2.5 feet, and 3 feet by 1.5 feet.
The 2 triangular sides have a base of 2 feet and a height of 1.5 feet.
Then the area of the triangle will be
⇒ 1/2 x 2 x 1.5
⇒ 1.5 square feet
The area of the rectangles will be
⇒ 3 x 2 + 3 x 2.5 + 3 x 1.5
⇒ 18 square feet
Then the surface area of the triangular prism will be
Surface area = 2 x 1.5 + 18
Surface arae = 3 + 18
Surface area = 21 square feet
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