Respuesta :

Answer:

x=3, HED =39

Step-by-step explanation:

Solution :

[tex]10x + 21 + 13x = 90[/tex]

[tex]23x = 90 - 21[/tex]

[tex]23x = 69 = > x = 3[/tex]

Angle HED = 13 × 3 = 39°

Hope this helps!