area = 63.585 yd²
circumference = 28.26 yd
Radius
Since the diameter of a circle is twice its radius, then the radius of this circle is half 9 yd:
radius = diameter ÷2
= 9 yd÷2 = 4.5 yd
The radius of this circle is 4.5 yd.
Area
The area of a circle is given by the equation:
[tex]area=\pi r^2[/tex]where r is the radius, then in this case:
[tex]\begin{gathered} area=\pi(4.5yd)^2 \\ \end{gathered}[/tex]Using π = 3.14
[tex]\begin{gathered} area=3.14\cdot(4.5yd)^2 \\ =3.14\cdot(4.5)^2yd^2 \\ =63.585yd^{2} \end{gathered}[/tex]Then, the area of this circle is 63.585 yd².
Perimeter
The perimeter of a circle is given by:
[tex]perimeter=2\pi r[/tex]where r is the radius, then:
[tex]perimeter=2\pi\cdot4.5yd[/tex]