Question

Alex has a rectangular plot of land with length 40 m and breadth 14 m. He builds a rectangular house with length 12 m and breadth 10 m as shown in the figure. Then, he decides to plant grass in the remaining part of the plot to convert it into a lawn The area of the lawn is a. 120 m b. 120 sq. m c. 340 sq. m d. 440 sq. m

Answer 1

Answer:

Radius (r) = 7 cm

height (h) = 10 cm.

Curved surface area of cylinder

2π/h

22

= 2 x 5 x 7 x 10

x 7 x 10 = 440 sq. cm.

7

Total surface area of cylinder

= 2tr(r + h)

22

= 2 x 5 x 7 (7+10)

= 44 x 17

= 748 sq.cm.

Ans. Curved surface area of cylinder is

440 sq cm and total surface area of cylinder

is 748 sq cm.

Answer 2

Answer:

Length of plot = 40m

breadth of plot = 14m

are of plot = 40 X 14

= 560m sq.

length of house = 12m

breadth of house = 10m

area of house = 12 X 1

= 120m sq.

remaining are for lawn = 560 - 120

. = 440m sq.

the option d is correct