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Trenton is building a skateboarding ramp in the shape of a triangular prism. According to his plan, the ramp would have a base of 2 feet, a height of 1.5 feet, and a length of 3 feet. The riding surface would measure 2.5 feet.
Area triangle = 1/2 *b * h = 1/2 * 2 * 1.5 = 1.5 ft^2
Area base = 2 *3 = 6 ft ^2
So, basically, to know the total surface, we just have to sum the are of both triangles, and the area of all three rectangles, as follows = 1.5 + 1.5 + 6 + 4.5 + 7.5 = 21 ft^2