# Subject : Mathematics

## Topic : Types of Angles and Shapes

Behavioural Objectives :  At the end of the lesson, the pupils should be able to

• Explain the meaning of triangles
• Give examples of triangles
• Mention types of triangles
• Say the properties of triangles

Previous Knowledge : Pupils have previous knowledge of       Polygons and plane figure       that was taught in the previous lesson

Instructional Materials :

• Pictures
• Wall Posters
• Related Online Videos
• Role Playing

Reference Materials

• Scheme of Work
• Online Information
• Textbooks
• Workbooks
• 9 Year Basic Education Curriculum

Content :

Types of Angles and Shapes

These are 4-sided plane shapes. They are rectangles, parallelograms, squares, rhombus,

kite and trapezium.

Rectangles

Opposite sides are equal.

Each of the interior angle is 90°.

Opposite sides are parallel

AB // CD

The two diagonals are AC and BD. Is AC = BD?

The two lines of symmetry are MN and ST. Is MN = ST?

Parallelograms

Opposite sides are equal and parallel.

A B

D C

None of the angles is equal to 90°

Is diagonal AC = BD?

How many lines of symmetry has parallelogram ABCD?

Squares

Opposite sides are equal parallel.

A B

D C

AB = CD = AD = BC

All the sides are equal.

Each of the interior angle is 90°.

Draw the lines of symmetry. How many are they?

Is AC = BD?

Rhombus

Opposite sides are equal and parallel. A B

C D

AB = CD and AD = BC

All the sides are equal.

AB = CD = AD = BC

None of the angles is equal to 90°.

Draw the diagonals AC and BD.

Measure AC and BD.

Is AC = BD?

How many lines of symmetry does a rhombus have?

Kite

Opposite sides are not equal.

How many lines of symmetry does a kite have?

Name them.

Draw the diagonals. How many are they?

Name the diagonals.

None of the interior angles is equal to 90°.

.

Trapezium

A pair of the opposite sides are parallel.

Two of the interior angles may be 90°.

How many lines of symmetry does a trapezium have?

These are two different types; see fig 1 and fig 2.

Draw the diagonals. How many are they?

Pentagon

A regular pentagon has 5 equal sides

and angles.

Here AB = BC = CD = DE = EA.

How many diagonals does a pentagon

have?

How many lines of symmetry does a

pentagon have?

Hexagon

A regular hexagon has 6 equal sides and

angles.

How many lines of symmetry does  pentagon ABCDEF have?

Heptagon

A regular heptagon has 7 equal sides and angles.

Octagon

A regular octagon has 8 equal sides and

angles.

.

Properties of different prisms

Properties of a cube

It has 6 equal faces. Each face is a square

It has 12 straight edges

All the edges are equal

It has 8 vertices (corners).

Properties of a cuboid

A cuboid has 6 faces

Some faces are either a

square or a rectangle

It has 12 straight edges

It has 8 vertices (corners).

Properties of a cylinder

A cylinder has 2 plane faces

The 2 plane faces are circular

It has 1 curved face

It has 2 curved edges.

Properties of a triangular prism

Presentation

The topic is presented step by step

Step 1:

The class teacher revises the previous topics

Step 2.

He introduces the new topic

Step 3:

The class teacher allows the pupils to give their own examples and he corrects them when the needs arise

Evaluation :

Assignment :