Question

class 10th
Sub:- Geometry

the ratio of circumference and area of a circle is 2:7 find its diameter

(A) 7 (B) 14 (C) 7/π (D) 14/π​

Answer 1

Answer:

Correct option is

(B) 14

Circumference = 7/2

2Πr/ Πr³= 7/2

r/2 = 7/2

r=7cm

Diameter =2×r =2×(7)=14cm

Answer 2

Answer:

$\frac{circumference}{area} = \frac{2}{7}$

$\frac{2\pi r}{\pi {r}^{2} } = \frac{2}{7}$

$\frac{2}{r} = \frac{2}{7}$

r=7cm

Circumference=

$2\pi \: r$

=2∗π∗7=

$14\pi \: cm$