There is an equilateral triangle that affects segment JKL. The exterior angle and the angle of two of the sides of the equilateral triangle are added in this case.
An equilateral triangle always has angles of 60-60-60. Therefore, you can find the angle of JKL with the following equation:
The maximum angle of a line is 180. The angles combined together are 200, so you will have to subtract the difference of 200 and 180 from the combined angles.