Question

If two sides of a triangle are 5cm and 9cm,then the third side is ?

Answer 1

5
$5 { }^{2} + third \: side { }^{2} = 9 { }^{2} \\ thirdside { }^{2} = 81 - 25 \\ thirdside {}^{2} = 56 \\ thirdside = \sqrt{56}$