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### Student Question

Hi ! In school I have to compare solids but I don’t understand how to compare them with faces and apex.  Thanks for your help.

Mathematics

## Explanations (1)

• Explanation from Alloprof

Explanation from Alloprof

This Explanation was submitted by a member of the Alloprof team.

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Team Alloprof • 1yr. edited September 2021

Hello, thank you for your question!

First, there are several ways to compare solids with faces and apex. Let's take the time to look at this together.

For faces, we can compare the number of faces of solids. For example, a cube is a solid that is formed only of square faces. If we take the time to count them, we can say that there are 6 faces. On the other hand, if we are looking for the number of faces of a square-based pyramid, there is a square face for the base + 4 triangle-shaped faces on the sides. So that's 5 sides. We can therefore say that the cube and the pyramid with a square base do not have the same number of faces.

We can also compare the shape of the faces. If we take the cube and the pyramid with a square base for this example, we can say that all the faces of the cube are faces of square shapes. However, the square-based pyramid has 1 square-shaped face, but also 4 triangular-shaped faces. They are therefore not faces of the same shape.

Finally, a vertex is an end of a solid that is formed by two edges that meet. We can therefore count the number of vertices. If we take a cube, there are 8 vertices. On the other hand, the square-based pyramid has 5 vertices.

Good evening,

Audrey