Page 193 - classs 6 a_Neat

EXAMPLE:11 How room many which is square 4 m tiles long and each 3 of m side broad? 0.5 m 9. In a rectangular park having a length of 45 m and width of 18 m, four corners of 32 m are demarcated for
will be required to pave the floor of a room which is 4m long and 3 m broad planting trees. Find the area of the park that can be used by the children for playing.
SOLUTION Length of the room = 4 m and its breadth = 3 m.
Area of the floor of the room = ( 4 × 3) m = 12 m 2 A 3 3 B
2
1 3 3 3 3
Each side of the square tile = 0.5 m = m.
2 3 3

2
Area of each square tile =   × 1  1  m 2 = 1 m.
 2  2 4

Required number of tiles= 12 ÷  1  =   × 12  4  = 48. 3 3

  4   1
Hence, 48 tiles are required to pave the floor of the room. 3 3 3 3
D 3 3 C
JUST TRY:1 Find the area of a handkerchief each side of which is 11 cm. AB= DC= 45 m AD= BC= 18 m
JUST TRY:2 Find the area of rectangular park whose length is 20 m and breadth 15 m.
JUST TRY:3 Find the cost of painting the ceiling of a room at the rate of t15 per m if the 10. A rectangular field is 75 m long and its breadth is 15 m less than its length. Find the cost of fencing it at the
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length is 15 m and the breadth 12 m. rate of ₹4 per metre. Also find the cost of turfing it at the rate of ₹7 per sq m. 1.How many times will a boy
JUSTTRY:4 A rectangular courtyard has to be paved with marble. The length of the courtyard is have to run round a square park whose length is 60 metres to cover as distance of 6 km?
25 m and its width is 18 m. The size of each marble slab is 9 sq m. How many 11. A rectangle is 16 m by 9 m. Find the side of a square whose area equals the area of the rectangle. By how
marble slabs will be required to pave the courtyard? much does the perimeter of the rectangle exceed the perimeter of the square?
JUST TRY:5 Arjun has a colourful sheet of paper of size 22 cm in length and 16 cm in breadth. He 12. What happens to the area of a rectangle if its length is halved and its breadth is doubled?
has to paste photographs of all his classmates on it. The size of each photograph is 4
cm X 2 cm. CIRCUMFERENCE OF A CIRCLE
How many photographs can he paste on one sheet? How many students are
there in Arjun’s class? CIRCUMFERENCE OF A CIRCLE The perimeter of a circle ts called its circumference. The length of the
thread that winds around the circle exactly once gives the circumference of the circle
EXERCISE 14-B
AN IMPORTANT RESULT the ratio of the circumference of a circle and its diameter is always constant.
1. The measure of the side of three squares are given here. Find the area of each This result can be verified with the help of the experiment given below.
square.
a. 15m b.1m 10m c. 7.5 cm EXPERIMENT Draw any three circles of different radii.
2. Find the area of a rectangular grassland whose length is 27 m and breadth 15 m. Measure the diameter of each one of them.
3. Find the cost of a plot of land that is 45 m long and 33 m broad given that the cost of land is ₹ 6,500 With the help of a tape or a thread, measure the circumference of each of them.
per square metre. Record them as given below.
4. 500 square tiles of side 25 cm are laid across the hall of a room. What is the area of the hall in sq m?
5. A rectangle is 81 m long and 36 m broad. Find the side of a square whose area is equal to the area of
this rectangle.
6. A room has a floor area of 15 m by 10 m. A square carpet of side 7 m is laid on the floor. How much
of the floor area is not carpeted?
7. The perimeter of a square lawn is 100 m. Find the area of the square lawn. What
will be cost of planting grass in the lawn at the rate of ₹13 per sq m?
8. Mr Gupta and Mr Mathur want to buy a plot of land each. The property dealer i ii iii
has a square plot and a rectangular plot of the same perimeter. The rectangular plot is 80 m long and Radius Diameter Circumference Circumferen ce  c
30 m broad, which Mr Gupta wants to buy. Does Circle (r) (2r) (C)  
Mr Mathur get the larger plot or the smaller one, and what is the difference in size? Diameter   2r
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