# Area & Preimeter

## Exercise 11.4

Question 1: A garden is 90 m long and 75 m broad. A path 5 m wide is to be built outside and around it. Find the area of the path. Also find the area of the garden in hectare.

Solution:Given; Length of the garden = 90m, Width of the garden = 75m, Width of the path around the garden = 5m

Area of rectangle = Length xx Width

= 90 xx75= 6750 m2

We know that, 10000 m2 = 1 hectare

Hence; 6750 m2 = 6750 ÷ 10000 = 0.675 hectare

Length of the garden with path = 90 m + 5m + 5m = 100 m

Width of the garden with path = 75 m + 5m + 5m = 95 m

Area of the garden with path = Length xx Width

= 100xx95= 9500 m

Now, Area of the path = Area of the garden with path — Area of the garden

= 9500 m2 — 6750 m2 = 2750 m2

Hence, Area of the path = 2750 m2, and area of the garden = 0.675 hectare

Question 2: A 3 m wide path runs outside and around a rectangular park of length 125 m and breadth 65 m. Find the area of the path. Solution: Given, Length of the park = 125m, Width of the park = 65m, Width of the path around the park = 3m

Therefore, Length of the park with path = 125m + 3m + 3m = 131m

Width of the park with park = 65m + 3m + 3m = 71m

Area of a rectangle = Length xx Width

Area of the park = 125 xx 65 = 8125 m2

Area of the park with path = Length xx Width

= 131xx71 = 9301 m2

Now, Area of the path = Area of the park with path — Area of the park

= 9301m2 — 8125m2 = 1176 m2

Question 3: A picture is painted on a cardboard 8 cm long and 5 cm wide such that there is a margin of 1.5 cm along each of its sides. Find the total area of the margin. Solution: Given, Length of the cardboard = 8cm, Width of the cardboard = 5cm, Margin left along each side of cardboard = 1.5cm

Hence, Length of the cardboard without margin = 8cm — 1.5cm — 1.5cm = 5cm

Width of the cardboard without margin = 5cm — 1.5cm — 1.5cm = 2cm

Area of the cardboard = Length xx Width

= 8xx5= 40 cm2

Area of the cardboard without margin = Length × Width

= 5xx2= 10 cm2

Therefore, Area of margin = Area of the cardboard — Area of the cardboard without margin

= 40cm2 — 10cm2= 30cm2

Question 4: A verandah of width 2.25m is constructed all along outside a room which is 5.5m long and 4m wide. Find
(i) The area of the verandah.
(ii) The cost of cementing the floor of the verandah at the rate of Rs 200 per m2. Solution: Given, Length of room = 5.5m, Width of room = 4m, Width of verandah which is constructed all along outside of room = 2.25m, Cost of cementing of verandha = Rs 200 per m2

Therefore, Length of room with verandah = 5.5m + 2.25m + 2.25m = 10m

Width of room with verandah = 4m + 2.25m + 2.25m = 8.5m

Area of room = Length xx width

= 5.5 xx 4= 22.0 m2

Area of room with verandah = Length xx Width

=10xx8.5 = 85 m2

Area of verandah = Area of room with verandah — Area of room

= 85m2 —22m2 = 63 m2

Cost of cementing of verandah = Area × Rate

Rs. 200 xx 63 = Rs. 12600