1. The radius of the circle is 3 m. What is the circumference of another circle, whose area is 49 times that of the first?
2. Two circles touch externally. The sum of their areas is 130 p sq. cm and the distance between their centres is 14 cm. Find the radii of the circles.
3. A wire when bent in the form of an equilateral triangle encloses an area of 121 √3 cm2 . If the same wire is bent in the form of a circle, find the area of the circle.
4. The area enclosed between the two concentric circles is 770 cm2. If the radius of the outer circle is 21 cm, calculate the radius of the inner circle.
5. A wheel of diameter 42 cm, makes 240 revolutions per minute. Find :
6. An arc of length 20pcm subtends an angle of 144° at the centre of the circle. Find radius of circle.
7. The perimeter of a sector of a circle of radius 5.7 m is 27.2 m. Find the area of the sector.
8. In the given figure, the length of the minor arc is 7/24 of the circumference of the circle. Find :
9. A chord of a circle of radius 10 cm subtends a right angle at the centre. Find :
10. A chord of a circle of radius 12 cm subtends an angle of 120° at the centre. Find the area of the corresponding segment of the circle. [use p = 3.14, √3 = 1.73]
11. In the given figure, ABC is an equilateral triangle inscribed in a circle of radius 4 cm. Find the area of the shaded region.
13. A paper is in the form of a rectangle ABCD in which AB = 20 cm and BC = 14 cm. A semi circular portion with BC as diameter is cut off. Find the area of the remaining part
15. In the following figure, ABC is an equilateral triangle. Circles are drawn with vertices of the triangle ABC as centers so that every circle touches the remaining two. If the perimeter of the triangle ABC is 84 cm.
16. Four equal circles are described at the four corners of a square so that each touches two of the others. The shaded area, enclosed between the circles is 24/7cm 2 . Find radius of the each circle.
17. Three horses are tethered with 7 m long ropes at the three corners of a triangular field having sides 20 m, 34 m and 42 m. Find the area of the plot which can be grazed by the horses. Also, find the area of the plot which remains ungrazed.
18. In the given figure, O is the centre of the bigger circle, and AC is its diameter. Another circle with AB as diameter is drawn. If AC = 54 cm and BC = 10 cm, find area of the shaded region.
19. A circle has been inscribed in a square of side 4 cm. Determine the left out area. What will be the left out area of the circle if a square is inscribed in the circle? [use p= 3.14]
20. In given Fig., ABC is a quadrant of a circle of radius 14 cm and a semicircle is drawn with BC as diameter. Find the area of the shaded region.