Respuesta :

Answer:

The answer is 12 because the other half is 8 and the other half is 12 so 12 + 8 is 22 So therefore its D

Step-by-step explanation:

Answer:

D). 12.

Step-by-step explanation:

Because the 2 angles at the vertex are equal we have the equation:

x / 21 = 8/(22-8)

x/ 21 = 8/14

x /21 = 4/7

7x  = 21*4

x = 84/7

x = 12.