angles that are supplementary add up to 180 degrees.
so you'll need to try adding up a few angles and summing then up to see which pair adds up to 180. you can also eliminate a few pairs by just seeing which ones couldn't add up to 180 (for example, 67 and 23).
113 + 67 = 180, so the answer is angle K and angle M.
hope this helped! please let me know if you are confused about anything i did