Explanation:
The perimeter of a trapezoid is All the sides combined. We already know two of the sides. You can simplify the square roots to be 2
+6+x. We know that two sides (or the ones we don't know) are equal, and we see an altitude. This shows that we can make a right triangle be a^2+b^2=c^2. Once we substitute everything, we find
^2(or 8)+x^2+c^2. This means that we now need to find x. Also, sorry, but I don't know what to do after this so I hope you can solve it from here. The things you need to find out are c^2 and x.