13. In this problem X is the angle in the right corner, since you are just scaling up the size of the triangle that means X is equal to the angle in the right side. I think we need more information to solve this. Are the two angles in the larger triangle the same? Does the two hash marks mean they are twice as large as the single? I think we need some more info to solve this.
14. X = 90 degrees; Since we are just doubling the two sides of the triangle and keeping the angles the same that means that X = 90 degrees.