Solution:
Given that,
Radius of circle = [tex]9x^2[/tex] units
To find: circumference of circle
The circumference of circle is given as:
[tex]C = 2 \pi r[/tex]
Where, r is the radius of circle
Substitute, r = [tex]9x^2[/tex]
[tex]C = 2 \times 3.14 \times (9x^2)\\\\C = 6.28 \times 9x^2\\\\C = 56.52x^2[/tex]
Thus circumference of circle is [tex]56.52x^2[/tex] units