Question

What us the approximate length of the diameter,d?

Answer 1

$\bf \textit{circumference of a circle}\\\\ C=2\pi r~~ \begin{cases} r = radius\\[-0.5em] \hrulefill\\ C=44 \end{cases}\implies 44=2\pi r\implies \cfrac{44}{2\pi }=r\implies \cfrac{22}{\pi }=r \\\\\\ \stackrel{\textit{diameter is 2r}}{2\cdot \cfrac{22}{\pi }}\implies \cfrac{44}{\pi }\qquad \approx \qquad 14.00563499208679$