Respuesta :

Answer:

x = 5

AB = 14 units

Step-by-step explanation:

From the picture attached,

In the given triangles ΔAEB and ΔCDB,

AE║CD and ED is a transverse,

∠EAB ≅ ∠DCB [Alternate interior angles]

AE║CD and AC is a transverse,

∠AEB ≅ ∠CDB [Alternate interior angles]

ΔAEB ~ ΔCDB by AA property of the similarity of two triangles.

Therefore, corresponding sides of these triangles will be proportional.

[tex]\frac{\text{AE}}{\text{CD}}=\frac{\text{BE}}{\text{BD}}=\frac{\text{AB}}{\text{BC}}[/tex]

[tex]\frac{\text{BE}}{\text{BD}}=\frac{\text{AB}}{\text{BC}}[/tex]

⇒ [tex]\frac{7}{4}=\frac{2x+4}{x+3}[/tex]

⇒ 7x + 21 = 8x + 16

⇒ 8x - 7x = 21 - 16

x = 5

AB = (2x + 4)

     = 10 + 4

     = 14 units