## Saturday, 7 December 2019

### Perimeter and Area (Practice Set 46)

Practice Set 46
1) The length and breadth of the page of a calendar is 45 cm and

26 cm respectively. What is its area?

-> The page of a calendar is rectangular shaped

Area of a rectangular page = Length X breadth

= 45 X 26

Area of a rectangular page = 1170 cm2

2) What is the area of the triangle with the base 4.8 cm and

height 3.6 cm?

-> Area of a triangle = ½ X base X height

= ½ X 4.8 X 3.6

= ½ X 17.28

= 17.28/2

Area of a triangle = 8.64 cm2

3) The length and breadth of a rectangular plot of land is

75.5 m and 30.5 m respectively. What is the cost of the plot at

the rate of 1000 Rs per square meter?

-> Area of a rectangular plot= length X breadth

= 75.5 X 30.5

= 2302.75m2

Now, The cost of the plot = rate X area

= 1000 X 2302.75

= 2302750 Rs

∴ The cost of the plot is Rs 230275.

4) A rectangular hall is 12 m long and 6 m broad. Its flooring is to

be made of square tiles of side 30 cm. How many tiles will fit in

the entire hall? How many would be required if the tiles of the

side 15 cm were used?

-> The area of the floor of the hall=length X breadth

= 12 X 6

∴The area of the floor of the hall = 72 m2

The area of 1square tiles = 30/100 X 30/100 =9/100 m2

The number of tiles required= area of the floor/ area of one tile

∴ 72 = 9/100     i.e 72 X 100 / 9     i.e =800

The area of 1square tiles is 15 cm

= 15/100 X 15/100 =9/100 m2

The number of tiles required= area of the floor/ area of one tile

∴ 72 = 9/100     i.e 72 X 100 / 15     i.e = 3200

5) From the information given in the figure, find the perimeter

and the area of the garden.

->This figure has 12 equal sides with each 13 m.

∴ Its perimeter = 13 X 12 = 156 m

This figure has 5 squares

∴ its area = 5 X 132     = 5 X 13 X 13  = 5 X 169   = 845m2.