Question

Find the circumference of a circle whose radius is 18 cm​

Answer 1

Answer:

circumference of circle is

$2\pi \: r \: \\ = 2 \times \frac{22}{7} \times 18 \\ = \frac{36 \times 22}{7} \\ = \frac{792}{7} \\ =113.14$

Answer 2

Given:-

•Radius of a circle is 18cm.

To Find:-

•Circumference of the circle.

Solution:-

we have,

• R = 18cm
• π = 22/7

Using Formula:

$\: \: \sf \: circumference \: of \: the \: circle = 2 \pi \: r$

Now substitute the values,

$\: \: \sf \: circumference \: of \: the \: circle = 2 \times \frac{22}{7} \times 18 \\ \\ \: \: \sf \: circumference \: of \: the \: circle = \frac{792}{7} cm = 113.14cm$

$\therefore$

Henceforth, Circumference of the circle is 113.14cm.

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Extra Info...

$\: \: \sf \implies \: area \: of \: the \: circle = \pi \: {r}^{2} \\ \\ \: \: \sf \implies \: radius \: of \: the \: circle = \frac{diameter}{2} \\ \\ \: \: \sf \implies \: diameter \: of \: the \: circle = 2 \times radius$

Radius: A line segment joining the centre and a point on the circle is called its radius.

Circumference: The perimeter of a circle is called its circumference.

Chord: A chord of a circle is a line segment joining any two points on the circle.

Diameter: A diameter is a chord of a circle passing through the centre of the circle.