NCERT TEXT BOOK EXERCISES
- Find the perimeter of each of the following figures:
- The lid of a rectangular box of sides 40 cm by 10 cm is sealed all round with tape. What is the length of the tape required?
- A table-top measures 2 m 25 cm by 1 m 50 cm. What is the perimeter of the table-top?
- What is the length of the wooden strip required to frame a photograph of length and breadth 32 cm and 21 cm respectively?
- A rectangular piece of land measures 0.7 km by 0.5 km. Each side is to be fenced with 4 rows of wires. What is the length of the wire needed?
- Find the perimeter of each of the following shapes:
(a) A triangle of sides 3 cm, 4 cm and 5 cm.
(b) An equilateral triangle of side 9 cm.
(c) An isosceles triangle with equal sides 8 cm each and third side 6 cm.
- Find the perimeter of a triangle with sides measuring 10 cm, 14 cm and 15 cm.
- Find the perimeter of a regular hexagon with each side measuring 8 m.
- Find the side of the square whose perimeter is 20 m.
- The perimeter of a regular pentagon is 100 cm. How long is its each side?
- A piece of string is 30 cm long. What will be the length of each side if the string is used to form:
(a) a square?
(b) an equilateral triangle?
(c) a regular hexagon?
- Two sides of a triangle are 12 cm and 14 cm. The perimeter of the triangle is 36 cm. What is its third side?
- Find the cost of fencing a square park of side 250 m at the rate of Rs 20 per metre.
- Find the cost of fencing a rectangular park of length 175 m and breadth 125 m at the rate of Rs 12 per metre.
- Sweety runs around a square park of side 75 m. Bulbul runs around a rectangular park with length 60 m and breadth 45 m. Who covers less distance?
- What is the perimeter of each of the following figures? What do you infer from the answers?
- Avneet buys 9 square paving slabs, each with a side of m. He lays them in the form of a square.
(a) What is the perimeter of his arrangement [figure (i)]?
(b) Shari does not like his arrangement. She gets him to lay them out like a cross. What is the perimeter of her arrangement [figure (ii)]?
(c) Which has greater perimeter?
(d) Avneet wonders if there is a way of getting an even greater perimeter. Can you find a way of doing this? (The paving slabs must meet along complete edges i.e. they cannot be broken.)
- Find the areas of the following figures by counting square:
- Find the areas of the rectangles whose sides are:
(a) 3 cm and 4 cm (b) 12 m and 21 m
(c) 2 km and 3 km (d) 2 m and 70 cm
- Find the areas of the squares whose sides are:
(a) 10 cm (b) 14 cm (c) 5 m
- The length and breadth of three rectangles are as given below:
(a) 9 m and 6 m
(b) 17 m and 3 m
(c) 4 m and 14 m
Which one has the largest area and which one has the smallest?
- The area of a rectangular garden 50 m long is 300 sq m. Find the width of the garden.
- What is the cost of tiling a rectangular plot of land 500 m long and 200 m wide at the rate of Rs 8 per hundred sq m?
- A table-top measures 2 m by 1 m 50 cm. What is its area in square metres?
- A room is 4 m long and 3 m 50 cm wide. How many square metres of carpet is needed to cover the floor of the room?
- A floor is 5 m long and 4 m wide. A square carpet of sides 3 m is laid on the floor. Find the area of the floor that is not carpeted.
- Five square flower beds each of sides 1 m are dug on a piece of land 5 m long and 4 m wide. What is the area of the remaining part of the land?
- By splitting the following figures into rectangles, find their areas (The measures are given in centimetres).
- (a) (b)
- Split the following shapes into rectangles and find their areas. (The measures are given in centimetres)
- How many tiles whose length and breadth are 12 cm and 5 cm respectively will be needed to fit in a rectangular region whose length and breadth are respectively:
(a) 100 cm and 144 cm
(b) 70 cm and 36 cm