Three Dimensional Shapes (3D) Basic 4 Mathematics Lesson Note

TOPIC

• Introduction
• Meaning and Properties of Three Dimensional Shape
• Lesson Evaluation

INTRODUCTION – 2D AND 3D SHAPES

Three dimensional shapes are objects or shapes that have three dimensions such as length, width, and height.

Three dimensional shapes are known as 3D shapes.

While two dimensional shapes have just two dimensions such as length and width.

Two dimensional shapes are also known as 2D shapes.

The properties of a three dimensional shapes are;

1. Faces
2. Edges
3. Vertices

TYPES OF THREE DIMENSIONAL SHAPES

The following shapes are the basic three dimensional shapes we see around us.

1. Cube
2. Cuboid (Rectangular prism)
3. Triangular prism
4. Sphere
5. Cone
6. Cylinder
7. Pyramid

CUBE

A cube is a solid three dimensional shape which has 6 square faces.

Examples of cube are ice cube, cube squares, dice, etc.

The cube has the following properties;

• 8 vertices (corners)
• 12 edges
• 6 faces

CUBOID

A cuboid is a solid three dimensional shape which has 6 rectangular faces or 4 rectangular faces and 2 square faces.

Six rectangular faces

Four rectangular faces with two square faces

Examples of cuboid are the lunch box, bricks, books, carton, cupboard, fridge, etc.

It is also called a rectangular prism.

The faces of the cuboid are a rectangle in shape.

The cuboid has the following properties;

• 8 vertices (corners)
• 12 edges
• 6 faces

TRIANGULAR PRISM

A triangular prism is a solid three dimensional shape which has 5 faces (2 triangular and 3 rectangular).

Examples of triangular prism are triangular ruler, camping tents, and chocolate candy bars.

The triangular prism has the following properties;

• 6 vertices
• 9 edges
• 5 faces

SPHERE

A sphere is a three dimensional round shaped object with just one face.

Examples of sphere ball, moon, sun, football, orange, etc.

The sphere has the following properties;

• No vertices
• No edges
• 1 curved face

CONE

A cone is a three dimensional object in solid with a circular base and has a single vertex.

Examples of cones are hat, ice cream cone, funnel, megaphone, christmas tree, traffic cone, etc.

The cone has the following properties;

• 1 vertices
• 1 edges
• 1 flat face – circle
• 1 curved face

CYLINDER

A cylinder is defined as a three dimensional shape with 2 circular bases connected by a curved surface.

Examples of cylinder poles, cans, cable, battery, gas cylinder, fire extinguisher, etc.

The cylinder has the following properties;

• 0 vertices
• 2 edges
• 2 flat faces – circles
• 1 curved face

PYRAMID

A pyramid is also a three dimensional shape with a square base and four triangular faces.

Examples of pyramids are the tent of a building, Egyptian pyramid, greenhouse pyramid, etc.

There are different types of pyramids depending on their bases.

So they first went to triangular base, square-based base but the most commonly used is square based.

The pyramid has the following properties;

• 5 vertices
• 8 edges
• 5 faces

LESSON EVALUATION

Teacher asks pupils to identify shapes from the

1. examples given.
2. real life examples in their environment.
3. differentiate between 2D and 3D shapes.
4. Name the properties of the shapes
5. state the uses of three dimensional shapes.
6. define dimensional shapes 2 and 3D definition.
7. state the properties of the following shapes;

• Cube
• Cuboid
• Sphere
• Triangular prism
• Cone
• Cylinder
• Pyramid