 # PRACTICE: 3D shapes

Lesson

## Practice

Let's go over some of the solids we've looked at. These include:

•  prisms
•  pyramids
•  cones
•  cylinders
•  spheres

### Examples

#### Example 1

Here is a rectangular prism.

a

How many faces does it have?

Worked Solution
Create a strategy

Faces are the flat sides of a solid.

Apply the idea

It has 6 faces.

b

How many vertices does it have?

Worked Solution
Create a strategy

Vertices are the corners where edges meet.

Apply the idea

It has 8 vertices.

c

How many edges does it have?

Worked Solution
Create a strategy

An edge is the line where two faces meet.

Apply the idea

It has 12 edges.

#### Example 2

Here is a square pyramid:

a

How many faces does it have?

Worked Solution
Create a strategy

Faces are the flat sides of a solid object.

Apply the idea

It has 5 faces: the 4 triangles and the 1 square base.

b

How many vertices does it have?

Worked Solution
Create a strategy

Vertices are the corners where two edges meet.

Apply the idea

It has 5 vertices.

c

How many edges does it have?

Worked Solution
Create a strategy

An edge is where two faces meet.

Apply the idea

It has 8 edges.

#### Example 3

Here is a cone.

a

How many faces does it have?

Worked Solution
Create a strategy

Faces are the flat sides of a solid object.

Apply the idea

It has 2 faces: the 1 triangular shape and 1 circle base.

b

How many vertices does it have?

Worked Solution
Create a strategy

In a cone, the vertex is the top point.

Apply the idea

It has 1 vertex.

c

How many edges does it have?

Worked Solution
Create a strategy

An edge is a straight line segment where two faces meet.

Apply the idea

It has 1 curved edge around the circle.

Idea summary
• Prisms and pyramids have only flat faces.
• Cones, spheres and cylinders have at least one curved face.

### Outcomes

#### MA2-14MG

makes, compares, sketches and names three-dimensional objects, including prisms, pyramids, cylinders, cones and spheres, and describes their features