Solve for x, given that the polygons are similar

In the question, we are given two polygons, and we are told that they are similar. Well, first, we can set up a proportion using the given sides and the side that we need to find. A suitable proportion would be . Now, in order to solve for we cross multiply. This gives us . Next, we add  to both sides. This gives us , and when we divide both sides by , we get that . Hope this helped!