Respuesta :

Answer:

Step-by-step explanation:

∠B=∠C (isosceles triangle)

so ⊥ AD bisects BC.

or BD=CD

2x-15=x+7

2x-x=7+15

x=22

AD=4x-6=22×4-6=82

DC=22+7=29

[tex]AC=\sqrt{(82^2+29^2)} =\sqrt{6724+841} =\sqrt{7565} \approx 86.977 \approx 86.98[/tex]