RS Aggarwal - Mathematics

Book: RS Aggarwal - Mathematics

Chapter: 18. Area of Circle, Sector and Segment

Subject: Maths - Class 10th

Q. No. 48 of Exercise 18A

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48

In the given figure PQSR represents a flower be. If OP = 21 m and OR = 14 m, find the area of the flower bed.

Given:

OP = 21 m = r1


OR = 14 m = r2


Let the quadrants made by outer and inner circles be Q1 and Q2, with radius r1 and r2 respectively.


Then, Area of flower bed = Area of Q1 – Area of Q2


∵ Area of Quadrant = πr2


∴ Area of Q1 = πr12


= × × 21 × 21


= m2


Similarly, Area of Q2 = πr22


= × × 14 × 14


= m2


Thus, Area of flower bed = -


= = 192.5 m2


Hence, the area of the flower bed is 192.5 m2.


Chapter Exercises

Exercise 18A
Exercise 18B
Multiple Choice Questions (MCQ)
Formative Assessment (Unit Test)

More Exercise Questions

1

The difference between the circumference and radius of a circle is 37 cm. Using π = 22/7, find the circumference of the circle.
2

The circumference of a circle is 22 cm. Find the area of its quadrant.
3

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4

If the area of a circle is numerically equal to twice its circumference, then what is the diameter of the circle?
5

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6

Find the length of the arc of a circle of diameter 42 cm which subtends an angle of 60° at the centre.
7

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8

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9

Find the perimeter of a semicircular protractor whose diameter is 14 cm.
10

Find the radius of a circle whose perimeter and area are numerically equal.
11

The radii of two circles are 19 cm and 9 cm. Find the radius of the circle which has circumference equal to the sum of the circumferences of the two circles.
12

The radii of two circles are 8 cm and 6 cm. Find the radius of the circle having area equal to the sum of the areas of the two circles.
13

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14

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15

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16

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17

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18

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19

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20

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21

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22

The area of the sector of a circle of radius 10.5 cm is 69.3 cm2. Find the central angle of the sector.
23

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24

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25

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26

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27

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28

In the given figure, OABC is a square of side 7 cm. If COPB is a quadrant of a circle wit centre C find the area of the shaded region.
29

In the given figure, three sectors of a circle of radius 7 cm, making angles of 60°, 80° and 40° at the centre are shaded. Find the area of the shaded region.
30

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31

In the given figure, find the area of the shaded region, if ABCD is a square of side 14 cm and APD and BPC are semicircle.
32

In the given figure, the shape of the top of a table is that of a sector of circle with centre O and ∠AOB = 90°. If AO = OB = 42 cm, then find the perimeter of the top of the table.
33

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34

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35

Find the perimeter of shaded region in the figure, if ABCD is a square of side 14 cm and APB and CPD are semicircles.
36

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37

In the given figure, APB and CQD are semicircle of diameter 7 cm each, while ARC and BSD are semicircles of diameter 14 cm each. Find the (i) perimeter, (ii) area of the shaded region.
38

In the given figure, PSR, RTQ and PAQ are three semicircles of diameter 10 cm, 3 cm and 7 cm respectively. Find the perimeter of shaded region.
39

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40

In the given figure, APB and AQO are semicircles and AO = OB. If the perimeter of the figure is 40 cm, find the area of the shaded region.
41

Find the area of a quadrant of a circle whose circumference is 44 cm.
42

In the given figure, find the area of the shaded region, where ABCD is a square of side 14 cm and all circles are of the same diameter.
43

Find the area of the shaded region in the given figure, if ABCD is a rectangle wit sides 8 cm and 6 cm ad O is the centre of the circle.
44

A wire is bent to form a square enclosing an area of 484 m2. Using the same wire, a circle is formed. Find the area of the circle.
45

A square ABCD is inscribed in a circle of radius ‘r’. Find the area of the square.
46

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47

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48

In the given figure PQSR represents a flower be. If OP = 21 m and OR = 14 m, find the area of the flower bed.
49

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50

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51

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