im pretty sure the length of the missing side is 144. I got this because a triangle can and has to add up to 180 or 180 degrees, so if you add 19 and 17 degrees you get 36 degrees. So there are two sides. To find the missing side you would have to subtract 36 degrees from 180 degrees (because a triangle has to be 180 degrees in total.) So therefore your answer is 144 degrees. 19 plus 17 = 36. 180 -36 = 144.
