Answer:
13
Step-by-step explanation:
It would have to be 13, because if you look at the top of the shape, you see the little 45 degrees. You can also see the 90 degrees right angle. Triangles no matter what add up to 180 degrees.
(a is the unknown angle in the bottom right)
90+45+a=180
45+a=90
a=45
now that we have that , we know that it has to be symmetrical.
so it can only be 13
hope this helps!
