Mariko has a bedroom wall that is shaped like a trapezoid with a height of 8 ft, a top base of 10 ft, and a bottom base of 13 ft. In the middle of this wall is a circular window whose radius is 2 ft. What is the area of the wall without the window? Use 3.14 for pi.
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First, you have to find the area of the entire wall, including the window. The formula for the area of a trapezoid is: A = (b1 + b2)/2 * h b1 is the first base, b2 is the second base, A is the total area, and h is the height. Plug in the numbers from the problem. (13 + 10)/2 * 8 Simplify. (23)/2*8 11.5*8 = 92 Now, to calculate the window's surface area, you use the formula for area of a circle. A = 3.14*r^2 Plug in your number. A = 3.14 * 2^2 Simplify. A = 3.14 * 4 A = 12.56 Now, you subtract the area of the window from the total area of the wall. 92 - 12.56 = 79.44 79.44 feet
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