The area of a circle is given by:
[tex]\begin{gathered} A=\pi r^2 \\ 167\pi=\pi r^2 \\ r=\pm\sqrt[]{167} \\ r=\pm\sqrt[]{167} \\ so\colon \\ r=\sqrt[]{167} \end{gathered}[/tex]since the diameter is twice the radius:
[tex]d=2\sqrt[]{167}\approx25.846[/tex]