Tbh the other guy gave the answer as 218 which I’m not sure is correct but if you see there is a straight line which is obviously 180 degrees and first I added 134 and 184 and it gives me 218 while also remember the fact that triangles are 180 degrees in total too..
First thing we need to do is find the inside angle at point L. Simply take the outside angle of 134 and subtract it from 180. 180-134 = 46. We then do the same for point M. 180-84 = 96. Finally, we add these together then subtract the sum from 360. 46+96 = 142. 360 - 142 = 218. The value of x is 218. Hope this helps!
When the corner is cut to a dimension of x, then the flap folded up, its height will be x. The appropriate choice is the last one, ... (25 -2x)(20 -2x)x