IXL | Surface area of pyramids

A triangular pyramid is shown below.

Which diagram is a net for this pyramid?

What is the surface area of the triangular pyramid?

square feet

ref_doc_title.

Learn with an example

question

A triangular pyramid is shown below.

Which diagram is a net for this pyramid?

What is the surface area of the triangular pyramid?

square inches

key idea

A net shows all the faces of a three-dimensional figure.

A triangular pyramid has four triangular faces. Its surface area is the sum of the areas of all four faces.

solution

Four faces make up the triangular pyramid:

one triangular face with a base of 11 inches and a height of 9.5 inches
three triangular faces with a base of 11 inches and a height of 7 inches

This is a net for the pyramid. It shows all of the faces and, when folded up, will form the pyramid.

To find the surface area, add up the areas of all four faces.

There is one triangular face with a base of 11 inches and a height of 9.5 inches. Find its area.

(

)

(

9.5

)

(

104.5

)

52.25

square inches

There are three triangular faces with a base of 11 inches and a height of 7 inches. Find the area of one of them.

(

)

(

)

(

)

38.5

square inches

Finally, find the sum of the areas of all four triangular faces.

(

38.5

)

52.25

115.5

52.25

167.75

The surface area of the triangular pyramid is 167.75 square

inches.

Looking for more? Try this:

Lesson: What is surface area?

$Confetti$

Excellent!

Now entering the Challenge Zone—are you ready?

Questions
answeredQuestions

Time
elapsedTime

hr	min	sec
00	00	01

SmartScore
out of 100
IXL's SmartScore is a dynamic measure of progress towards mastery, rather than a percentage grade. It tracks your skill level as you tackle progressively more difficult questions. Consistently answer questions correctly to reach excellence (90), or conquer the Challenge Zone to achieve mastery (100)! Learn more

Teacher tools

Work it out

Not feeling ready yet? These can help:

FF.3Nets of three-dimensional figures

GG.6Area of triangles

Surface area of cubes and rectangular prisms

Lesson: What is surface area?

Excellent! You got that right!

Jumping to level 1 of 1

Excellent!