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E:\Working\Focus_Learning\Math_Genius_5_(05-10-2023)\Open_Files\CHAP_11
\\November 22, 2023 5:10 PM Surender Prajapati Proof 5 Reader _________________________ Date: ___________________74

Area of part 1 = Area of yellow square Area of part 1 = Area of yellow rectangle

= 5 × 5 = 25 sq. units = 6 × 3 = 18 sq. units
25
Area of yellow triangle = sq. units 18
2 Area of yellow triangle = = 9 sq. units
= 12.5 sq. units 2
Area of part 2 = Area of pink square Area of part 2 = Area of green rectangle

= 25 sq. units = 8 × 6 = 48 sq. units
Area of pink triangle = 25 sq. units 48
2 Area of green triangle = 2 = 24 sq. units
So, area of the given triangle So, area of the given complete triangle
= Area of yellow triangle + Area of pink
triangle = 12.5 + 12.5 = 25 sq. units = 9 + 24 = 33 sq. units

example: In the adjacent figure, find the area of triangle PQR. P
Solution: Area of rectangle A = 3 × 5 sq. units
A B
= 15 sq. units

Area of rectangle B = 3 × 5 sq. units
= 15 sq. units Q R

15 15 1 1
So, area of triangle PQR = + = 7 + 7 = 15 sq. units.
2 2 2 2

practice time 11B

1. Find the area of rectangle whose:

(a) length = 20 cm, breadth = 12 cm (b) length = 11.5 cm, breadth = 10 cm

(c) length = 132 cm, breadth = 80 cm (d) length = 4.5 m and breadth = 180 cm

2. Find the area of a square with side:

(a) 4.2 cm (b) 64 cm (c) 8.5 m (d) 6.2 cm
3. Complete the following tables.

Length of the rectangle (cm) Breadth of the rectangle (cm) Area (sq. cm)
(a) 9 4.5
(b) 32 1600
(c) 15 345

(d) 8.5 51
4. Find the area of the shaded part in each.

(a) (b) (c) (d)

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