If `A` is the area and `C` is the circumference of a circle, then its radius is
(a)`A/C`
(b) `(2A)/C`
(c)`(3A)/C`
(d) `(4A)/C`

Find the circumference of a circle whose area is 301. 84\ c m^2 .

The ratio of the area and circumference of a circle of diameter d is (a) d (b) d/2 (c) d/4 (d) 2\ d

The circumference of a circle is 44 cm. Its area is (a)77 c m^2 (b) 154 c m^2 (c)208 c m^2 (d) 144 c m^2

If the difference between the circumference and radius of a circle is 37 cm, then its area is (a) 154\ c m^2 (b) 160\ c m^2 (c) 200\ c m^2 (d) 150\ c m^2

The area of a circle of circumference C is (a) (C^2)/(4pi) (b) (C^2)/(2pi) (c) (C^2)/pi (d) (4C^2)/pi

The ratio of the perimeter (circumference) and diameter of a circle is (a) pi\ (b) 2pi (c) pi/2 (d) pi/4

If the circumference and the area of a circle are numerically equal, then diameter of the circle is (a) pi/2 (b) 2pi (c) 2 (d) 4

Find the rate of change of the area of a circle with respect to its radius r when(a) r = 3 c m (b) r = 4 c m

AB is a diameter of a circle and C is any point on the circumference of the circle. Then a) the area of A B C is maximum when it is isosceles b) the area of A B C is minimum when it is isosceles c) the perimeter of A B C is minimum when it is isosceles d) none of these

The circumferences of two circles are in the ratio 3: 4. The ratio of their areas is (a) 3:4 (b) 4:3 (c)9:16 (d) 16 :9