The given triangle has unequal sides and unequal angles. This means that it is a scalene triangle. The sum of angles in a triangle is 180 degrees. This means that
Angle L + angle K + angle J = 180 degrees. Therefore
5x + 2x + 3x = 180 degrees
10x = 180
Dividing the left hand side of the equation and the right hand side of the equation by 10, it becomes