McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
5. Volumes of Pyramids and Cones
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Exercise 39 Page 846

Compare the formulas to find the volume of a prism and a pyramid. Recall you want them to have the same base and volume. Look for a relation between their heights.

See solution.

Practice makes perfect

The formulas to find the volume of a prism and the volume of a pyramid are shown below.

Volume Formulas
Prism Pyramid
V_1 = B_1h_1 V_2 = 1/3B_2h_2

We want a prism and a pyramid with the same base and volume. That is, B_1=B_2 and V_1=V_2. B_1=B_2 & (I) V_1=V_2 & (II) ⇒ B_1=B_2 B_1h_1 = 1/3B_2h_2 By substituting Equation (I) into Equation (II), we get a relation between the heights of the figures. B_2h_1 = 1/3B_2h_2 ⇒ h_1 &= 1/3h_2 ⇒ h_2 &= 3h_1 From the above, we get that the height of the pyramid must be three times the height of the prism. With that said, we can proceed to draw a prism and a pyramid with the same base and volume.

Keep in mind that the figures above are just a sample, so your answer may vary.