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Perimeter
## Perimeter and Circumference.

### How to get the Perimeter of plain shapes

#### 1. Rectangle

#### 2. Square

#### 3. Full circle

#### 4. Semi circle

## KCPE Topical Questions

### Perimeter and Circumference

The distance around a shape is called its **perimeter**.

The perimeter of a circle is its **circumference.**

- To find the perimeter of a plain shape like a
**rectangle**, use the formula**2(***L*+*W)*

- To find the perimeter of a
**square**use**4 X***L*

- To get the circumference of a
**full circle**use**π***d*

- To get the distance all round a
**half a circle**, get the circumference of the half circle and the diameter. Use the formula**π***d*+*d*

- To get the distance all round a figure made up of various shapes then add up the measurements.

Class 7

1. The figure below is a semi-circle of diameter 14 metres. What is the perimeter of the figure? (Take pi - 22/7).

A. 77 m B. 36 m C. 22 m D. 58 m

2. Wanyama wants to put a fence round his rectangular plot 36 m long and 30 m wide. The interval between the posts is 3 m and the cost of each fencing post is sh 10.

Calculate the amount of money Wanyama will require to buy fencing posts.

A. Sh 450 B. Sh 220 C. Sh 440 D. Sh 3600

3. In the figure below, the diameter of the semicircle is 21 cm. What is the perimeter of the figure in centimeters? (Take 22/7)

A. 335 B. 323 C. 290 D. 302

4. The diagram below represents Ojil’s piece of land. He put a fence around it. How many posts did he use if the spacing between the posts was 3 metres?

A. 120 B. 90 C. 360 D. 121

5. The figure below represents a flower garden. The diameter PQRS of the larger semicircle is 28 m. the diameter QR of the smaller semicircle is 14 m.

What is the perimeter of this garden?

A. 66 m B. 80 m C. 146 m D. 231 m

6. A rectangular plot of land length 44 m has an area of 1760 m^{2}. What is the perimeter of this plot of land?

A. 84 m B. 128 m C. 176 m D. 168 m

7. A bicycle wheel has a radius of 35 cm. What distance, in kilometres, does the wheel cover the wheel after 100 revolutions? (Take pi - 22/7)

A. 0.22 B. 2.2 C. 22 D. 220

8. Mwaka used 44 pegs to mark around a circular animal shed. The interval between the pegs was 3 m. What is the radius of the shed? (Take pi - 22/7)

A. 132 m B. 42 m C. 7 m D. 21 m

9. The diagram below shows Amalemba’s piece of land. He put a fence around it.

How many posts did he use if the spacing between the posts was 4 metres?

A. 54 B. 79 C. 80 D. 81

10. A wheel covers a distance of 44 metres after making 10 revolutions. What is the radius of the wheel in metres? (Take pi - 22/7)

A. 0.7 m B. 1.4 m C. 2.2 m D. 7.0 m

11. The diagram below shows Wanja’s plot of land.

What is the perimeter of the plot?

A. 300 B. 280 C. 270 D. 230

12. The diagram below represents a vegetable garden. One of its edges is a semi-circle.

What is the perimeter of the garden? (Take pi - 22/7)

A. 455 m B. 356 m C. 320 m D. 160 m

13. The diagram below shows a running track whose dimensions are given in metres. The end of the track are semi-circular.

What is the perimeter of the track? (Take pi - 22/7)

A. 198 m B. 301 m C. 328 m D. 400 m

14. The figure below represents a plot surrounded by a part of a circular path and two straight paths. The two straight paths, each measuring 6.3 m, are also radii of the circle meeting at a right angle.

What is the total length of the path surrounding the plot? (Take pi - 22/7)

A. 12.6 m B. 29.7 m C. 39.6 m D. 42.3 m

15. The length of a side of a square plot of land is 26 m. A farmer left a space of 2 m for the gate and fenced round the remaining part with 3 strands of wire. What was the total length of the wire used?

A. 306 m B. 310 m C. 102 m D. 312 m

16. A design was made of straight edges of lengths 2.1 cm and arcs of circles of radii 2.1 cm as shown in the diagram below.

What is the perimeter of the design? (Take pi - 22/7)

A. 36.12 cm B. 34.8 cm C. 26.4 cm D. 21.6 cm

17. The figure below represents a vegetable garden.

What is the perimeter of the garden?

A. 39 m B. 51 m C. 54 m D. 60 m

18. The design below is made up of a pair of parallel lines each 3 cm long, two small half-circles each of diameter 7 cm and two large half circles each of diameter 14 cm.

What is the perimeter of the design? (Take pi - 22/7)

A. 39 cm B. 66 cm C. 72 cm D. 136.5 cm

19. The figure below represents a plot of land.

How many poles, one metre apart, will be needed to fence the plot?

A. 171 B. 170 C. 169 D. 150