Question

Area and Circumference of Circles (A)Calculate the area and circumference of each circle.r=9.5 mmr=2.7 cmcircumferencearea =circumferencearea =

Answer 1

Part 1

r=9.5 mm

The area is given by the formula

`\begin{gathered} A=pi*r^2 \\ A=pi*9.5^2 \\ A=90.25pi\text{ mm}^2 \end{gathered}`

The circumference is given by the formula

`\begin{gathered} C=2*pi*r \\ C=2*pi*9.5 \\ C=19pi\text{ mm} \end{gathered}`

Part 2

r=2.7 cm

Find out the area

`\begin{gathered} A=pi*2.7^2 \\ A=7.29pi\text{ cm}^2 \end{gathered}`

Find out the circumference

`\begin{gathered} C=2*pi*2.7 \\ C=5.4pi\text{ cm} \end{gathered}`

Part 3

r=7.3 in

Area

`\begin{gathered} A=pi*7.3^2 \\ A=53.29pi\text{ in}^2 \end{gathered}`

Circumference

`\begin{gathered} C=2*pi*7.3 \\ C=14.6pi\text{ in} \end{gathered}`