What is the area of this figure?

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Work Shown:
Break up the figure as shown in the diagram below.
A rectangle and trapezoid form
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Area of rectangle = base*height = 9*15 = 135 cm^2
Area of trapezoid = (1/2)*(b1+b2)*h = (1/2)*(18+9)*12 = 162 cm^2
total area = (area of rectangle)+(area of trapezoid)
total area = (135) + (162)
total area = 297 square cm