Class 10 Mathematics

# Area of Circle

## Exercise 12.2 (NCERT Book) Part 1

**Solution:** Area of sector

**Solution:** Radius can be calculated as follows:

Area of quadrant can be calculated as follows:

**Solution:** The minute hand makes an angle of 360^{o} in 60 minutes.

Hence, angle made in 5 minutes = 30^{o}

Area of sector

**Solution:**Area of minor sector

Area of major sector

Area of triangle formed by two radii

Area of minor segment = Area of minor sector – area of triangle

= 25π - 50 = 25(π - 2)

= 25(3.14 – 2) = 25 x 1.14 = 28.5 sq cm

the length of the arc area of the sector formed by the arc area of the segment formed by the corresponding chord

**Solution:** Length of Arc can be calculated as follows:

Area of corresponding sector can be calculated as follows:

As the angle made by radii is 60^{o}, so this is an equilateral triangle; because angles opposite to both radii will be equal.

Area of equilateral triangle can be calculated as follows:

**Solution:** Let us use previous figure to find area of triangle

Area of circle = πr^{2} = π15^{2} = 225π = 706.5 sq cm

Area of minor sector

Area of minor segment = 117.75 – 97.425 =20.325 sq cm

Area of major segment = 706.5 – 20.325 = 686.175 sq cm

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Exercise 1

Exercise 2 (Part 2)

Exercise 3 (Part 1)

Exercise 3 (Part 2)