use the Pythagorean Theorem. [tex] a^{2} [/tex] + [tex] b^{2} [/tex] = [tex] c^{2} [/tex]
so it would, [tex] 12^{2} [/tex] + [tex] 16^{2} [/tex] = [tex] c^{2} [/tex]
so what you do now is simplify [tex] 12^{2} + 16^{2} [/tex], which will equal 400.
so now you have [tex] c^{2} =400[/tex], so then you square root 400 to get rid of the squared.
[tex] \sqrt{ c^{2} } = \sqrt{400} [/tex]
[tex] \sqrt{400} = 20[/tex]
so your unknown side is 20 :P
