The diameter of the circumference is 7 yd. Its radius is half the diameter, then:
[tex]\begin{gathered} r=\frac{7}{2}yd \\ \\ r=3.5yd \end{gathered}[/tex]
The area of a circle is given by the following formula:
[tex]A=\pi\cdot r^2[/tex]
Where r is the radius, 3.5 yd in this case. We can replace the values and calculate it now:
[tex]\begin{gathered} A=3.14\cdot(3.5yd)^2 \\ A=3.14\cdot12.25yd^2 \\ A=38.465yd^2 \end{gathered}[/tex]
The area of the circle is 38.465 square yards.
To calculate the circumference we use the following formula:
[tex]C=2\cdot\pi\cdot r[/tex]
Again, we just need to replace the values:
[tex]\begin{gathered} C=2\cdot3.14\cdot3.5yd \\ \\ C=6.28\cdot3.5yd \\ \\ C=21.98yd \end{gathered}[/tex]
The circumference of the circle is 21.98 yards.
