Why the volume formulas work (Cavalieri's principle)
Grade 10 Math Worksheet

Circle the best answer, or write your answer on the line.
Kira leans a stack of coins into a slanted can shape. Why does it hold the same as a straight can with the same base and height?
- Because leaning cans are always smaller.
- Because you use the slanted side as its height.
- At every height, both have the same circle slice.
- It holds more, because its slanted side is longer.
Milo pushes a box-shaped stack of cards so it leans. Why is its volume still the base area times the height?
Sketch: a straight stack of cards and the same stack leaning, the same height straight up. Sketch: a straight stack of cards and the same stack leaning, the same height straight up. Sketch: a straight stack of cards and the same stack leaning same height straight up Not to scale. - Because the slanted edge is now the height.
- Because the stack is a cube.
- Each card keeps its area, and the stack is the same height.
- Leaning adds space between the cards, so it holds more.
Noah stacks 10 square paper plates straight, then twists another 10 so their corners turn. Why do the two stacks have the same volume?
Sketch: a straight stack of square paper plates beside a twisted stack, the same height. Sketch: a straight stack of square paper plates beside a twisted stack, the same height. straight stack twisted stack same height - They don't: turned squares make different slices.
- Twisting adds corners, so it holds more.
- Each turned plate still has the same area at its height.
- Twisting packs them tighter, so it holds less.
Pia's clay can has radius and height 6 cm, with a cone scooped out, tip at the bottom center. What is the area of its slice 2 cm up, in terms of π (like 14π)?
Sketch: the can (radius 6 cm, height 6 cm) with a cone hole whose tip is at the center of the bottom and whose top is the can's top circle; a cut 2 cm up. Sketch: the can (radius 6 cm, height 6 cm) with a cone hole whose tip is at the center of the bottom and whose top is the can's top circle; a cut 2 cm up. the can with a cone hole whose tip is at the center of the bottom and whose top is the can's top circle; a cut 2 cm up 6 cm 6 cm cone hole Not to scale. Ren's clay can has radius and height 7 cm, with a cone scooped out, tip at the bottom center. What is the area of its slice 3 cm up, in terms of π (like 14π)?
Sketch: the can (radius 7 cm, height 7 cm) with a cone hole whose tip is at the center of the bottom and whose top is the can's top circle; a cut 3 cm up. Sketch: the can (radius 7 cm, height 7 cm) with a cone hole whose tip is at the center of the bottom and whose top is the can's top circle; a cut 3 cm up. cut cone hole radius 7 cm height 7 cm 3 cm up center of bottom Tala's clay can has radius and height 9 cm, with a cone scooped out, tip at the bottom center. What is the area of its slice 5 cm up, in terms of π (like 14π)?
Sketch: the can (radius 9 cm, height 9 cm) with a cone hole whose tip is at the center of the bottom and whose top is the can's top circle; a cut 5 cm up. Sketch: the can (radius 9 cm, height 9 cm) with a cone hole whose tip is at the center of the bottom and whose top is the can's top circle; a cut 5 cm up. radius 9 cm height 9 cm cut 5 cm up cone hole can Zee's clay can has radius and height 5 cm, with a cone scooped out, tip at the bottom center. What is the area of its slice 2 cm up, in terms of π (like 14π)?
Sketch: the can (radius 5 cm, height 5 cm) with a cone hole whose tip is at the center of the bottom and whose top is the can's top circle; a cut 2 cm up. Sketch: the can (radius 5 cm, height 5 cm) with a cone hole whose tip is at the center of the bottom and whose top is the can's top circle; a cut 2 cm up. can with a cone hole 5 cm 5 cm cone hole tip at the center of the bottom; top is the can's top circle; cut 2 cm up Not to scale. Read this first
Sketch, not to scale
The leaning cone with radius 3 cm, the height 11 cm drawn straight up from the base to the tip's level, and its longest side 12 cm.
Ari's clay volcano leans: radius 3 cm, height 11 cm straight up, and its longest side is 12 cm. What is its volume in cubic cm, in terms of π (like 14π)?
Bo's leaning ice cream cone leans: radius 6 cm, height 5 cm straight up, and its longest side is 8 cm. What is its volume in cubic cm, in terms of π (like 14π)?
Sketch, not to scale: the leaning cone with radius 6 cm, the height 5 cm drawn straight up from the base to the tip's level, and its longest side 8 cm. Sketch, not to scale: the leaning cone with radius 6 cm, the height 5 cm drawn straight up from the base to the tip's level, and its longest side 8 cm. leaning cone 5 cm 6 cm 8 cm height drawn straight up from the base to the tip's level longest side 8 cm Not to scale. Use this
Sketch, not to scale: the leaning cone with radius 9 cm, the height 4 cm drawn straight up from the base to the tip's level, and its longest side 15 cm.
Jun's leaning sand volcano leans: radius 9 cm, height 4 cm straight up, and its longest side is 15 cm. What is its volume in cubic cm, in terms of π (like 14π)?
Sketch, not to scale: the leaning cone with radius 9 cm, the height 4 cm drawn straight up from the base to the tip's level, and its longest side 15 cm. Sketch, not to scale: the leaning cone with radius 9 cm, the height 4 cm drawn straight up from the base to the tip's level, and its longest side 15 cm. 4 cm 9 cm 15 cm