RECTANGLESTRIANGLES

PARALLELOGRAMS TRAPEZIUMS

COMBINED SHAPES IN EVERYDAY LIFE

FLOOR DESIGN HOUSE

AREA OF RECTANGLE = LENGTH X BREADTHAREA OF RECTANGLE = LENGTH X BREADTH

A B

2 cm

4 m2 cm

6 m

Area of A = 2 cm x 2cm = 4 cm²

Area of B = 6 m x 4 m = 24 m²

AREA OF TRIANGLE = ½ X BASE X HEIGHT

C D

2 cm

8 m 4m

6 cm

Area of C = ½ x 2cm x 6 cm = 6cm²

Area of D = ½ x 4m x 8 m = 16m²

AREA OF PARALLELOGRAM = AREA OF PARALLELOGRAM = BASE X HEIGHTBASE X HEIGHT

4 cm E

5 cm

Area of E = 4 cm x 5 cm

= 20 cm²

AREA OF TRAPEZIUM = AREA OF TRAPEZIUM = ½ x ( a + b ) x h½ x ( a + b ) x h

4 cm

6 cm

5 cm F

Area of F = ½ x ( 4 cm + 6 cm ) x 5 cm = ½ x 10 cm x 5 cm = 25 cm²

Area of F = ½ x ( 4 cm + 6 cm ) x 5 cm = ½ x 10 cm x 5 cm = 25 cm²

To find areas of figures made up of trianges, rectangles, parallelograms or trapeziums

Example 1

Area of triangle = ½ x 8cm x 6 cm = ½ x 48cm² = 24cm²

Solution

Area of square = 4 cm x 4 cm = 16 cm²

Area of the figure = 24cm² + 16 cm² = 40cm²

4 cm

8 cm

4 cm

Example 2

7m

4m

Area of rectangle = 7m x 4m = 28 m²

Area of triangle = ½ x 7m x 6 m = ½ x 42 m² = 21 m²

Area of the figure = 28 m² +21 m² = 49 m²

6 m

Example 3

AB

C

Area of A = ½ x 3 m x 3 m = ½ x 9 m² = 4.5 m²

Area of B = 10 m x 3 m = 30 m²

Area of C = ½ x 3 m x 3 m = ½ x 9 m² = 4.5 m²

Area of the figure = (4.5 m² + 30 m²) + 4.5 m² = 34.5 m² 4.5 m² = 39 m²

10 m

3 m

Example 4

Area of D = ½ x (6 cm + 8 cm) x 7 cm = 49 cm²

Area of E = ½ x 5 cm x 8 cm = ½ x 40 cm² = 20 cm²

Area of the figure = 49 cm² + 20 cm² = 69 cm²

8 cmD

5 cm

6 cm

7 cm

E