GED Math : GED Math

Study concepts, example questions & explanations for GED Math

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Example Questions

Example Question #132 : 3 Dimensional Geometry

A regular tetrahedron has four congruent faces, each of which is an equilateral triangle. 

A given tetrahedron has edges of length five inches. Give the total surface area of the tetrahedron.

Possible Answers:

Correct answer:

Explanation:

The area of an equilateral triangle is given by the formula

.

Since there are four equilateral triangles that comprise the surface of the tetrahedron, the total surface area is 

.

Substitute :

 square inches.

Example Question #1651 : Ged Math

A cube has a height of 9cm.  Find the surface area. 

Possible Answers:

Correct answer:

Explanation:

To find the surface area of a cube, we will use the following formula:

where l is the length, and w is the width of the cube.

Now, we know the height of the cube is 9cm. Because it is a cube, all lengths, widths, and heights are the same. Therefore, the length and the width are also 9cm.

Knowing this, we can substitute into the formula. We get

Example Question #1652 : Ged Math

A sphere has a radius of 7in.  Find the surface area.

Possible Answers:

Correct answer:

Explanation:

To find the surface area of a sphere, we will use the following formula:

where r is the radius of the sphere.

Now, we know the radius of the sphere is 7in. 

So, we can substitute into the formula. We get

Example Question #681 : Geometry And Graphs

Find the surface area of a cube with a length of 12in.

Possible Answers:

Correct answer:

Explanation:

To find the surface area of a cube, we will use the following formula:

where l is the length, and w is the width of the cube.

Now, we know the length of the cube is 12in. Because it is a cube, all sides are equal. Therefore, the width is also 12in. So, we can substitute. We get

Example Question #1653 : Ged Math

A cube has a height of 8cm. Find the surface area. 

Possible Answers:

Correct answer:

Explanation:

To find the surface area of a cube, we will use the following formula:

where l is the length, and w is the width of the cube.

Now, we know the height of the cube is 8cm. Because it is a cube, all lengths, widths, and heights are the same. Therefore, the length and the width are also 8cm.

Knowing this, we can substitute into the formula. We get

Example Question #132 : 3 Dimensional Geometry

A sphere has a radius of 5in. Find the surface area. 

Possible Answers:

Correct answer:

Explanation:

To find the surface area of a sphere, we will use the following formula:

where r is the radius of the sphere.

Now, we know the radius of the sphere is 5in.

So, we can substitute into the formula. We get

Example Question #1654 : Ged Math

Find the surface area of a cube with a height of 13in.

Possible Answers:

Correct answer:

Explanation:

To find the surface area of a cube, we will use the following formula:

where l is the length, and w is the width of the cube.

Now, we know the length of the cube is 13in. Because it is a cube, all sides are equal. Therefore, the width is also 13in. So, we can substitute. We get

Example Question #141 : 3 Dimensional Geometry

Find the surface area of a sphere with a radius of 8in.

Possible Answers:

Correct answer:

Explanation:

To find the surface area of a sphere, we will use the following formula:

where r is the radius of the sphere.

Now, we know the radius of the sphere is 8in.

Knowing this, we can substitute into the formula. We get

Example Question #142 : 3 Dimensional Geometry

Sphere

Give the surface area of the above sphere.

Possible Answers:

Correct answer:

Explanation:

Given the radius  of a sphere, the surface area  can be calculated using the formula

.

Set  in the formula and evaluate:

Example Question #692 : Geometry And Graphs

A cube has a width of 8in. Find the surface area.

Possible Answers:

Correct answer:

Explanation:

To find the surface area of a cube, we will use the following formula:

where l is the length, and w is the width of the cube.

Now, we know the width of the cube is 8in. Because it is a cube, all sides/lengths are equal. Therefore, the length is also 8in. So, we can substitute. We get

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