To calculate the circumference of a circle, you can use the formula:
\[ C = 2\pi r \]
where \( C \) is the circumference, \( r \) is the radius, and \( \pi \) is approximately 3.14.
Given that the radius \( r = 90 \):
\[ C = 2 \times 3.14 \times 90 \]
Calculating it step-by-step:
\[ C = 2 \times 3.14 = 6.28 \] \[ C = 6.28 \times 90 = 565.2 \]
So, the approximate circumference of the circle is 565.2 when expressed to the tenths place.