**Area of Quadrilaterals**

Starter

Area of a parallelogram.

Area of a Kite

**L.O. - To find the area of different named quadrilaterals.**

base

height

Area = base x height

Does the area of the rectangle change when it changes into a parallelogram?

What does that mean for how we calculate the area of a parallelogram?

A kite is made up of two triangles.

Which line is the base of both

triangles?

What is the combined height of

both triangles?

Therefore what is the combined

area of both triangles (i.e. the area

of the kite)?

a

b

h

Two of these trapezia can

be put together to create

a parallelogram.

a

a

h

b

b

What is the base of the parallelogram?

What is the area of the parallelogram?

What is the area of a single trapezium?

Area of a Trapezium (Level 7)

Area of Quadrilaterals

Area of a Parallelogram

= base x height.

height

base

diagonal 2

diagonal 1

Area of a Kite =

diagonal 1 x diagonal 2 2

a

height

b

Area of Trapezium =

(a + b) x height 2

Sheet Answers:

(1) 12 cm (2) 36 cm (3) 96 m (4) 12.8 m

(5) 51 mm (6) 300 mm (7) 45.5 m (8) 58.5 mm

(9) 20 Km (10) 42 m (11) 60 cm (12) 25.2 cm

2

2

2

2

2

2

2

2

2

2

2

2

Always/Sometimes/Never

If a triangle and a trapezium have the same base

they will have the same area.

If a parallelogram and a trapezium have the same base they will have the same area.

If a triangle and a trapezium have the same base

and height the trapezium will have more area.

Area of Quadrilaterals

4 cm

7 cm

16 mm

9 mm

3 m

7 m

9 m

Area of Quadrilaterals

4 cm

7 cm

16 mm

9 mm

3 m

7 m

9 m

Area = 4 x 7 = 28cm

Area = 9 x 16/2 = 72 mm

Area = (3+9) x 7/2 = 42 m

2

2

2

Starter

(a) 30 cm

(b) 10.825 cm

(c) 64.95 cm

2

2

Activity

Complete the area sheet.

Always/Sometimes/Never

If a triangle and a trapezium have the same base

they will have the same area.

Sometimes

If a parallelogram and a trapezium have the same base they will have the same area.

Sometimes

If a triangle and a trapezium have the same base

and height the trapezium will have more area.

Always

**Activities**

**Activity**

Answers

Answers

**Key**

Examples

and

Notes

Examples

and

Notes

**Worked**

Example

Example