\(\sqrt{5-\sqrt{13+4\sqrt{3}+\sqrt{3+\sqrt{13+4\sqrt{3}}}}}\)
\(=\sqrt{5-\sqrt{13+4\sqrt{3}+\sqrt{3}+1}}\)
\(=\sqrt{5-\sqrt{14+5\sqrt{3}}}\)
\(=\dfrac{\sqrt{10-2\sqrt{14+5\sqrt{3}}}}{\sqrt{2}}\)
\(=\dfrac{\sqrt{10-\sqrt{2}\cdot\left(\sqrt{5}+3\right)}}{\sqrt{2}}\)
\(=\dfrac{\sqrt{10-\sqrt{10}-3\sqrt{2}}}{\sqrt{2}}\)
\(=\dfrac{\sqrt{20-2\sqrt{10}-6\sqrt{2}}}{2}\)
\(\sqrt{5}-\sqrt{13}+4\sqrt{3}+\sqrt{3}+4\sqrt{3}+13\)
=27.21897397