Respuesta :
Solution:
The formula for calculating the circumference of a circle is given by;
[tex]\begin{gathered} C=2\pi R\ldots\ldots\ldots\ldots.......\ldots\ldots\ldots\text{......}\mathrm{}(\text{when the radius is given)} \\ \\ OR \\ \\ C=\pi D\ldots\ldots\ldots....\ldots\ldots....\ldots\ldots\ldots\ldots\ldots\text{.......}\mathrm{}(\text{when the diameter is given)} \end{gathered}[/tex]Question 1:
[tex]\begin{gathered} when \\ D=4in,\pi=3.14 \\ C=\pi D \\ C=3.14\times4 \\ C=12.56in \\ \\ \\ D=6in,\pi=3.14 \\ C=\pi D \\ C=3.14\times6 \\ C=18.84in \\ \\ \\ \\ D=12in,\pi=3.14 \\ C=\pi D \\ C=3.14\times12 \\ C=37.68in \end{gathered}[/tex]Question 2:
[tex]\begin{gathered} \text{when} \\ R=2ft,\pi=3.14 \\ C=2\pi R \\ C=2\times3.14\times2 \\ C=18.84ft \\ \\ \\ R=14ft,\pi=3.14 \\ C=2\pi R \\ C=2\times3.14\times14 \\ C=87.92ft \\ \\ \\ \\ R=12ft,\pi=3.14 \\ C=2\pi R \\ C=2\times3.14\times12 \\ C=75.36ft \end{gathered}[/tex]Question 3:
[tex]\begin{gathered} \text{when} \\ R=9ft,\pi=3.14 \\ C=2\pi R \\ C=2\times3.14\times9 \\ C=56.52ft \\ \\ \\ R=11ft,\pi=3.14 \\ C=2\pi R \\ C=2\times3.14\times11 \\ C=69.08ft \\ \\ \\ \\ R=7ft,\pi=3.14 \\ C=2\pi R \\ C=2\times3.14\times7 \\ C=43.96ft \end{gathered}[/tex]
Question 4:
[tex]\begin{gathered} when \\ D=10ft,\pi=3.14 \\ C=\pi D \\ C=3.14\times10 \\ C=31.4ft \\ \\ \\ R=9ft,\pi=3.14 \\ C=2\pi R \\ C=2\times3.14\times9 \\ C=56.52ft \\ \\ \\ \\ D=13ft,\pi=3.14 \\ C=\pi D \\ C=3.14\times13 \\ C=40.82ft \end{gathered}[/tex]
Question 5:
The circular track represents a circle.
Given:
[tex]D=2\text{miles}[/tex]The distance around the track represents the circumference of the circular track.
Hence, we find the circumference using the formula below;
[tex]\begin{gathered} C=\pi D \\ C=3.14\times2 \\ C=6.28\text{miles} \end{gathered}[/tex]Therefore, the distance around the race track is 6.28 miles
