Respuesta :

Answer:

You would do this problem like a normal varible problem. x=10

Step-by-step explanation:

Since 9x is a right angle the inside would also be 9x

9x+4x+10+40=180

180 because that is how much a triangle equals

combine like terms

13x+50=180

subtract 50 from both sides

13x=130

divide by 13

x=10

Hope this helps!