Area = width * height
since the window is 20 inches higher than the width:
width +20 = height
640 = width * width+20
640 = width^2 +20*width
width^2 +20*width - 640 = 0
width = 17.203
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Double Check
if width = 17.203 then height = 37.203
area = 17.203 * 37.203 = 640 square inches Correct!!
If it is isosceles, than the legs are the same. We will call them X. The formula for the area of a triangle is 1/2 (base * height). But the base and the height are both X. So the area (18) is equal to 1/2 (x * x), or 1/2(x^2). This means that 36 = x^2. Thus, the length of each side is 6 inches. You can check this work by plugging those into the formula for area. You will find that it equals 18.
Answer:
D. He forgot to subtract the area of the base from the total surface area of the cube.
Step-by-step explanation:
He is only spray washing the *exterior* of the building; the base is not exposed so it will not be spray washed, which means Richard can use less water.
Hope this helps. :)
5/6......5 out of 6.......using division, it is 5 divided by 6 = 0.833
