[tex]\large\boxed{\begin{array}{l} \sf{a {}^{2} = b {}^{2} + c {}^{2} } \\ \\ \sf{10 {}^{2} = 8 {}^{2} + B {}^{2} } \\ \\ \sf{100 = 64 + B {}^{2} } \\ \\ \sf{100 - 64 =B {}^{2} } \\ \\ \sf{B {}^{2} \: = \: 36} \\ \\ \sf{B = \sqrt{36} } \\ \\ \boxed{ \boxed{ \sf{B = 6 \: cm}}}\end{array}}[/tex]
