Question

AB is a triangle, right angled at A if AB= 42 , AC=3cm. Find BC

Answer 1

Answer:

${ac}^{2} = {ab}^{2} + {bc }^{2} \\ {3}^{2} = {42}^{2} + {bc}^{2} \\ 9 = 1764 + {bc}^{2} \\ 1764 - 9 = {bc}^{2} \\ 1755 = {bc}^{2} \\ bc = \sqrt{1755 } \\ bc = 41.89272$