Answer:
d = 52 in
C = 6π mm²
Explanation:
The formula of a circumference:
![C=2\pi r=d\pi](https://img.qammunity.org/2020/formulas/mathematics/middle-school/avv0t1675znboo9z6ips7p24v5v5e4sclh.png)
r - radius
d - diameter
We have
.
Calculate the diameter using
:
divide both sides by π
![d=52\ in](https://img.qammunity.org/2020/formulas/mathematics/middle-school/6xreuqll7glqr3yh97teu555uiixtnqd83.png)
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If a circle inscribed in a square, then the diameter of a circle and a side of a square are congruent (have the same length).
We have the area of the square:
![A=36\ mm^2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wwepuwn92nitj63l7cyy3vovo2ybkle2kh.png)
The formula of an area of a square:
![A=s^2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7qjqar9k4ynqdm5a89kdy8hazgw5jtmal8.png)
s - side
Substitute:
![s^2=36\to s=√(36)\\\\s=6\ mm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dl7t10cui5gk5xl0dzfntdfe2oav3hzxps.png)
The formula of a circumference
![C=d\pi](https://img.qammunity.org/2020/formulas/mathematics/high-school/lpvc6u5o55rc8sl7kswdrwf9o5utdk6j41.png)
d - diameter
d = s → d = 6 mm
Substitute:
![C=6\pi\ mm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/fl3xidkw36t9w65uptgsgej136mff9k2h1.png)