McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
4. Volumes of Prisms and Cylinders
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Exercise 12 Page 834

Use the formula for the volume of the prism.

324 cm^3

Practice makes perfect

The given solid is a prism.

The volume of a prism can be calculated using the following formula, where B is the area of the base and h is the height. V=Bh Let's first calculate the area of the base B. We can see that the base is a right triangle, so we can use the known formula to find its area. B = 1/2 ab However, we only know that a=9cm. To find b, we can use the Pythagorean Theorem. a^2+b^2=c^2 We can see that the length of one of the legs is a = 9cm and the length of the hypotenuse is c = 15cm. We can use this information to find the length of b.
a^2+b^2=c^2
9^2 + b^2 = 15^2
â–Ľ
Solve for b
81 + b^2 = 225
b^2 = 144
b = sqrt(144)
b = 12
Since a negative side length does not make sense, we only need to consider positive solutions. Therefore, the length of the second arm of our triangle is b = 12cm. Finally, we can calculate the area of our prism's base.
B = 1/2 ab
B= 1/2( 9)( 12)
B = 54
The base area of the prism is 54cm^2. We can also see that the height equals 6cm. Let's substitute these values into the formula and solve for V.
V=Bh
V=( 54)( 6)
V=324
The volume of the prism is 324cm^3.