McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
2. Surface Areas of Prisms and Cylinders
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Exercise 8 Page 817

Use the formula for the surface area of the prism.

7 inches

Practice makes perfect
The given solid is a prism. To calculate the surface area of a prism, we can use the known formula where P is the perimeter of the base, h is the height, and B is the area of the base. S=Ph+2B The base of a cube is a square, this means that the base has four equal side lengths. Let's add them to find the perimeter of the base. P&=s+s+s+s P&= 4 s Now, we can calculate its area using the formula for area of a square. B&= s * s B&= s^2 Finally, we have enough information to find the length of a lateral edge of the cube. Let's substitute S with 294 square inches, P with 4s, h with s, and B with s^2 into the formula.
S=Ph+2B
294=( 4s)( s)+2( s^2)
â–Ľ
Simplify right-hand side
294 = 4s^2 +2s^2
294 = 6s^2
49 = s^2
7 = s
s=7
The length of a lateral edge of a cube is 7inches.