Question

PLEASE HELP ME can someone explain and give the answer

Answer 1

`{eb}^(2) = {ab}^(2) + {ea}^(2) \\ {ab}^(2) = {eb}^(2) - {ea}^(2) \\ {ab}^(2) = {20}^(2) - {12}^(2) \\ ab = 16 \\ \\ {db}^(2) = {bc}^(2) + {dc}^(2) \\ {bc}^(2) = {db}^(2) - {dc}^(2) \\ {bc}^(2) = {20}^(2) - {16}^(2) \\ bc = 12 \\ \\ so \: ac = ab + bc \\ ac = 28`