Page 208 - Start Up Mathematics_6

5. Cost of levelling a rectangular plot is obtained by multiplying area of the rectangle with per
unit cost of levelling.
Area of tile
6. The number of tiles required to cover a wall is .
Area of wall
Fill in the Blanks

1. The area of a closed figure is measured in ____________ and its perimeter in _____________.
2. The area of a square whose each side measures p cm is _________.
3. A circle can always be inscribed in a _________ polygon.

4. The number of tiles whose length and breadth are 9 cm and 4 cm respectively that will cover
a rectangular region measuring 243 cm × 124 cm is _____________.
Answer in One Word or a Line
1. What is the perimeter of a regular decagon of side 5 cm?

2. If the side of the square is given in centimetres (cm), what will be the unit of its area?
3. If the side of a rhombus is given in metres (m), in what unit will its perimeter be measured?
What will be the perimeter?
4. If perimeter of a field is 2 km, how many metres (m) of barbed wire is required to fence it?
5. If the area of a square field is given in km , by what factor should it be multiplied to convert
2
it into m ?
2

let’s evaluate
1. Find the measure of the side of a regular hexagon whose perimeter is 96 cm.
2. Find the breadth of a rectangle whose perimeter is 880 m and length is 315 m.
3. What happens to the area of a square if its side is halved?

4. An athlete takes 10 rounds of a rectangular park 200 m long and 100 m wide. Find the total
distance covered by him.

5. What happens to the area of a rectangle, if the length is doubled and the breadth remains the
same?

6. A rectangular piece of plot measures 0.5 km by 0.4 km. Each side is to be fenced with 4 rows
of wires. What is the length of wire needed? If the wire costs ` 11 per metre, what will be the
cost of wire required for fencing?

7. A stick, assumed to be 1 m long, measured the sides of a rectangular field. The area thus
calculated was 900 sq. m. Later on, it was discovered that the actual length of the stick is
90 cm. Find the correct area of the rectangular field.

8. A room is 5 m 10 cm long and 4 m 90 cm wide. How much carpet is required to cover the
room? What will be the cost of the carpet, if 1 sq. m of carpet costs ` 600?

9. The cost of laying grass in a rectangular park at the rate of ` 10 per sq. m is ` 4,800. Find the
cost of constructing its boundary at the rate of ` 800 per m if the park is 20 m wide.

Thinking Skills

1. How can you show that the area of square A is less than
the area of square B without measuring the sides? A B
[Hint: Use tracing paper]

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