Final answer:
Supplementary angles sum up to 180 degrees. The equation that represents supplementary angles 1 and 2 is m<1 + m<2 = 180°, aligning with option c.
Step-by-step explanation:
The question asks which equation represents the relationship between the measurements of angles 1 and 2 which are supplementary. Supplementary angles are two angles whose measurements add up to 180 degrees. Therefore, the correct equation that represents the relationship between their measurements is m<1 + m<2 = 180°, which corresponds to option c.