We know that a line and a triangle is 180 degrees when added together. First we find JLK because JLM is already to be found at 140 degrees.
180-140 = 40 degrees —> angle JLK
now we find KJL
We know that triangle angles also add up to 180 degrees
75+40 = 115 —> 180-115=65
Angle KJL = 65 degrees