Question

help pls it is kinda hard

Answer 1

Answer

step

${bc}^{2} + {ac}^{2} = {ab}^{2}$

${bc}^{2} = {ab}^{2} - {ac}^{2}$

let bc=x

${ x}^{2} = {13}^{2} - {8}^{2}$

${x}^{2} = 169 - 64$

${x}^{2} = 105$

$x = \sqrt{105}$