Diameter is defined as the line passing through the center of a circle having two extremes on the circumference of a circle.

The Diameter of a circle divided the circle into two equal parts known as semi-circle.

The center of a circle is the midpoint of its diameter. It divides the diameter into two equal parts, each of which is a radius of the circle. The radius is half the diameter.

We all know that A **chord** of a circle is a straight line segment whose endpoints both lie on the circle. Thus it can be said that the diameter is the longest possible chord on any circle.

**Relation between Radius and Diameter:**

We know that the the distance from the center point to any point on the circumference of a circle is a fixed distance, known as the Radius of a circle.

Therefore, the relation between Radius and Diameter is

\(Diameter = 2 \times Radius\)

**Formula for Area and circumference in Terms of Diameter:**

**Circumference:**

We know

Circumference = \(2 \pi r\)

It can be re-written as, \( (2r) \times \pi\)

= \(d \times \pi\)

**Area:**

We know

Area= Â \(\pi r^{2}\)

It can be re-written as \( \frac{\pi (2r)^{2}}{4}\)

\(= \frac{\pi}{4}.d^{2}\)

Given, Radius of the circle (r) = 8 cm Diameter of the circle = 2r = 2 $\times$ 8 cm = 16 cm Now Area
= 200.96
Given, Area of the circle (A) = 154 We know Area (A)
Now Finding the Circumference of a circle which is equal to,
= 44 cm |