Intermediate Geometry : Cubes

Study concepts, example questions & explanations for Intermediate Geometry

varsity tutors app store varsity tutors android store

Example Questions

1 2 3 4 5 6 8 Next →

Example Question #71 : Solid Geometry

A sphere with a radius of  is cut out of a cube that has a side length of . What is the volume of the resulting figure?

Possible Answers:

Correct answer:

Explanation:

Since the cube is bigger, we will be subtracting the volume of the sphere from the volume of the cube.

Start by recalling how to find the volume of a sphere.

Plug in the given radius to find the volume.

Next, recall how to find the volume of a cube:

Plug in the given side length to find the volume of the cube.

Finally, subtract the volume of the sphere from the volume of the cube.

Make sure to round to  places after the decimal.

Example Question #72 : Solid Geometry

Pyramid

The above figure shows a triangular pyramid inscribed inside a cube. The pyramid has volume 100. Give the volume of the cube.

Possible Answers:

Correct answer:

Explanation:

Let  be the length of one side of the cube. Then the base of the pyramid is a right triangle with legs of length . The area of a right triangle is half the product of the lengths of the legs, so the base has area

The volume of a pyramid is one third the product of its height and the area of its base. The height of the pyramid is , so the volume is

The volume of the cube is , so

,

or, equivalently,

That is, the volume of the cube is six times that of the pyramid, and, since the pyramid has volume 100, the volume of the cube is .

1 2 3 4 5 6 8 Next →
Learning Tools by Varsity Tutors