A regular tetrahedron has 4 triangular faces. The area of one of these faces is given by:

Because the surface area is the area of all 4 faces combined, in order to find the area for one of the faces only, we must divide the surface area by 4. We know that the surface area is , therefore:

Since we now have the area of one face, and we know the height of one face is , we can now plug these values into the original formula:

Therefore, the length of the base of one face is .

A regular tetrahedron has 4 triangular faces. The area of one of these faces is given by:

Because the surface area is the area of all 4 faces combined, in order to find the area for one of the faces only, we must divide the surface area by 4. We know that the surface area is , therefore:

Since we now have the area of one face, and we know the height of one face is , we can now plug these values into the original formula:

Therefore, the length of the base of one face is .

The diagonal of a shape is simply the length from a vertex to the center of the face or vertex opposite to it. With a regular tetrahedron, we have a face opposite to the vertex, and this basically amounts to calculating the height of our shape.

We know that the height of a tetrahedron is where s is the side length, so we can put into this formula:

which gives us the correct answer.

The problem is essentially asking us to go from a three-dimensional measurement to a two-dimensional one. In order to approach the problem, it's helpful to see how volume and surface area are related.

This can be done by comparing the formulas for surface area and volume:

We can see that both calculation revolve around the edge length.

That means, if we can solve for (edge length) using volume, we can solve for the surface area.

Now that we know , we can substitute this value in for the surface area formula:

The diagonal of a shape is simply the length from a vertex to the center of the face or vertex opposite to it. With a regular tetrahedron, we have a face opposite to the vertex, and this basically amounts to calculating the height of our shape.

We know that the height of a tetrahedron is where s is the side length, so we can put into this formula:

which gives us the correct answer.

The problem is essentially asking us to go from a three-dimensional measurement to a two-dimensional one. In order to approach the problem, it's helpful to see how volume and surface area are related.

This can be done by comparing the formulas for surface area and volume:

We can see that both calculation revolve around the edge length.

That means, if we can solve for (edge length) using volume, we can solve for the surface area.

Now that we know , we can substitute this value in for the surface area formula:

If this is a regular tetrahedron, then all four triangles are equilateral triangles.

If the slant height is , then that equates to the height of any of the triangles being .

In order to solve for the surface area, we can use the formula

where in this case is the measure of the edge.

The problem has not given the edge; however, it has provided information that will allow us to solve for the edge and therefore the surface area.

Picture an equilateral triangle with a height .

Drawing in the height will divide the equilateral triangle into two 30/60/90 right triangles. Because this is an equilateral triangle, we can deduce that finding the measure of the hypotenuse will suffice to solve for the edge length ().

In order to solve for the hypotenuse of one of the right triangles, either trig functions or the rules of the special 30/60/90 triangle can be used.

Using trig functions, one option is using .

Rearranging the equation to solve for ,

Now that has been solved for, it can be substituted into the surface area equation.

If this is a regular tetrahedron, then all four triangles are equilateral triangles.

If the slant height is , then that equates to the height of any of the triangles being .

In order to solve for the surface area, we can use the formula

where in this case is the measure of the edge.

The problem has not given the edge; however, it has provided information that will allow us to solve for the edge and therefore the surface area.

Picture an equilateral triangle with a height .

Drawing in the height will divide the equilateral triangle into two 30/60/90 right triangles. Because this is an equilateral triangle, we can deduce that finding the measure of the hypotenuse will suffice to solve for the edge length ().

In order to solve for the hypotenuse of one of the right triangles, either trig functions or the rules of the special 30/60/90 triangle can be used.

Using trig functions, one option is using .

Rearranging the equation to solve for ,

Now that has been solved for, it can be substituted into the surface area equation.

The only given information is the surface area of the regular tetrahedron.

This is a quick problem that can be easily solved for by using the formula for the surface area of a tetrahedron:

If we substitute in the given infomation, we are left with the edge being the only unknown.

The only given information is the surface area of the regular tetrahedron.

This is a quick problem that can be easily solved for by using the formula for the surface area of a tetrahedron:

If we substitute in the given infomation, we are left with the edge being the only unknown.