Question

EXERCISE 10.1
1. Find the perimeter of the rectangle in which:
(a) Length - 14.8 m, Breadth = 5.5 m
(b) Length = 16 m 50 cm, Breadth = 11 m 25 cm
2. Find the perimeter of a square having length of each side as:
(a) 5.6 m (b) 24.5 cm
3. A man takes two rounds of a regular pentagon of side 125 m. Find the distance covered by him.
4. Find the perimeter of a triangle
(a) having sides 10 cm. 12 cm and 15 cm
(b) having each side as 14 cm
(C) isosceles triangle having equal sides as 40 cm and third side as 20 cm
5. There is a rectangular lawn 10 m long and 4 m wide in front of Meena's house as shown in figure. It is fenced along the two smaller sides and
one longer side leaving a gap of 1 m for the entrance. Find the length of fencing.
6. Find the side of a square whose perimeter is 124 cm.​

Answer 1

Answer:

1. (a) 40.6m (b) 55.5m

2. (a) 22.4 (b) 98

3. 1250m

4. (a) 37cm (b) 42cm (c) 100cm

5. 12m

6. 31cm

Step-by-step explanation:

1. perimeter of rectangle= length*2 + breadth*2

(a) 14.8*2+5.5*2 = 40.6   (b) 16.50*2+11.25*2 = 55.5m

2. perimeter of square= side*4

(a) 5.6*4=22.4   (b) 24.5*4=98

3. pentagon= 5 sides

125*5= 625

rounds taken= 2

625*2= 1250

4. perimeter of triangle= side+side+side

(a) 10+12+15=37cm

(b) 14+14+14=14*3=42

(c) 40+40+20=40*2+20=80+20=100

5.  fencing is 1m apart from the lawn, which means fencing is 1m longer from each side i.e. 4+1+1= 6. Two smaller sides, which means that length of fencing= 6*2= 12m

6. perimeter of square= 124cm

side of square= 124/4 = 31cm