If the circumference of a circle is 55 cm, then its diameter is ……

1.	If the circumference of a circle is 55 cm, then its diameter is ………………. cm. A) 18 B) 17.5 C) 17 D) 16.5
Answer» Correct option is B) 17.5 Let radius of the circle be r cm. \(\therefore\) circumference of the circle is P = 2 π r But given that circumference of the circle be 55 cm. \(\therefore\) 2 π r = 55 ⇒ 2 x 22/7 x r = 55 ⇒ r = 55 x 7/22 x 1/2 = 35/4 cm Now, the diameter of the circle is 2r = 35/2 = 17.5 cm

If the circumference of a circle is 55 cm, then its diameter is ………………. cm. A) 18 B) 17.5 C) 17 D) 16.5

Answer»

Correct option is B) 17.5

Let radius of the circle be r cm.

\(\therefore\) circumference of the circle is P = 2 π r

But given that circumference of the circle be 55 cm.

\(\therefore\) 2 π r = 55

⇒ 2 x 22/7 x r = 55

⇒ r = 55 x 7/22 x 1/2 = 35/4 cm

Now, the diameter of the circle is 2r = 35/2 = 17.5 cm