Answer: X=5
Step-by-step explanation:
Since the triangles are similar shape-wise, then that means that the sides are going to be similar numerically.
12/4 got us 3, which is the side of that smaller triangle. Since we divided 12 by 4, then we need to divide 20 by 4 to get the unknown side. 20/4 is 5, therefore x is 5.
