College Math

Solution: The given diagram can be divided into two parts that is a rectangle and a trapezoid, by drawing a straight line parallel to AB and ED, shown here: Now, if we find the area of the rectangle ABCF and trapezoid CDEF and add them, we get the area of the entire figure. The area of rectangle is calculated as base*height where, BC = base = 8cm and AB = height = 15cm. Area of rectangle = 15*8 = 120 cm 2 Area of trapezoid is given by the formula, Area = ½ (b 1 + b 2 ) *h Now, BC = AF = 8. AE = AF + FE 20 = 8 + FE FE = 12 cm = height of trapezoid Also, AB = FC = 15 = base of trapezoid Finally, b 1 = 10, b 2 = 15 and h = 12 Thus, area of CDEF = ½*(10+15)*12 = 150 cm 2 Therefore, the area of ABCDE = 120+150 = 270cm 2 7. a

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