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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
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 tr iangle = 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