I took five years before and it was hard for me to remember the postualates. I found it helpful to practice proving problems that involved the postualate. Some postualates like SAS are just abbreviations. SAS- Side-Angle-Side
143.44 degrees
Hope this helps (:
I believe that x=20 from the math i did hopefully its helpful.
There are 3 feet in 1 yard so each foot is 1/3