To calculate the number of shingles, we first calculate for the total area of the roof of Janice's house. From the figure, we can calculate the area of the two shapes: pyramid and a rectangular prism.
A(pyramid) = lw+l√[(w/2)²+h²]+w√[(l/2)²+h²]
A = 208 m²
A(prism) = 2(wl+hl+hw)
A = 293 m²
Total area = 501 m²
Number of shingles she needs = 501 m² / 2.25 m² =<span> 223</span><span>
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Answer : C
hope that helps
Area of rectangle = LxW = 13x7 = 91
Area of triangle = bxh/2 = 7x7/2= 24.5
Total area= 91+24.5= 115.5 in^2