I don’t know how to do this help

Answer: 140 degree
Step-by-step explanation: The line LMU is basically 180, so what you'll do is 90 degree KLM plus 50 degree LMK which will give you 140 degree. A whole triangle is a supplementary angle so it's 180 degree. To find KMU, you do (180 - 140) - (180 - 40) = 140. So the answer for angle KMU is 140.