[tex]\bf 4\pi \qquad \approx \qquad 12.57 \\\\[-0.35em] ~\dotfill\\\\ \sqrt{79}+\sqrt{63}\qquad \approx \qquad 8.89 + 7.94\implies 16.83 \\\\[-0.35em] ~\dotfill\\\\ \sqrt{143}\qquad \approx \qquad 11.96 \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill \stackrel{11.96}{\sqrt{143}}\qquad \stackrel{12.57}{4\pi }\qquad \stackrel{16.83}{\sqrt{79}+\sqrt{63}}~\hfill[/tex]
