Question

Find the area and the circumference of a circle with diameter 4cm.Write your answers in terms of π, and be sure to include the correct units in your answers.

Answer 1

Given:

Diameter of a circle is 4cm

Required:

To find the area and circumference of a given circle.

Step-by-step explanation:

Given that the diameter is 4cm.

Therefore, the radius of the circle is

`\begin{gathered} r=(4)/(2) \\ =2cm \end{gathered}`

The formula for area of a circle is,

`A=\pi r^2`

Substitute the value of r, we get

`\begin{gathered} A=\pi2^2 \\ =4\pi \end{gathered}`

The formula for circumference of a circle is,

`\begin{gathered} C=2\pi r \\ =2*\pi*2 \\ =4\pi \end{gathered}`

Final Answer:

Area of a circle,

`A=4\pi`

Circumference is

`C=4\pi`