Respuesta :

SINAZEUS
the answer is 41


if AE is 20, so AD is 40.

the measure of angle CDA is 90 degrees.

so we can get help from Pythagorean theorem :
[tex] {x}^{2} = {40}^{2} + {9}^{2} \\ {x}^{2} = 1600 + 81 = 1681 \\ x = \sqrt{1681} = 41[/tex]



good luck