Lesson

Being able to identify the key features of shapes can help us in this lesson.

Does a circle have straight or curved edges?

A

Straight

B

Curved

Worked Solution

Idea summary

Edges can be straight or curved.

A straight edge goes from one vertex to another without any bends.

A curved edge has a bend.

This video looks at cones, spheres, and cylinders. All these shapes have curved surfaces. Let's see how we can tell which one is which.

Here is a cone.

a

How many faces does it have?

Worked Solution

b

How many vertices does it have?

Worked Solution

c

How many edges does it have?

Worked Solution

Idea summary

- A curved surface is a surface that is not flat.
- A surface that is flat with a curved edge is still a flat surface.
- Cylinders, cones and spheres all have a curved surface but they do not all have flat surfaces.