In a triangle, the measure of angles is in the same order of size as the order of the lengths of the opposite sides.
The largest angle is opposite the longest side.
The smallest angle is opposite the smallest side.
The mid-sized angle is opposite the mid-sized side.
The longest side measures 6 ft. The angle opposite that side is angle M.
Angle M is the largest angle.
The second longest side measures 5.5 ft. The angle opposite that side is angle N. Angle N is the second largest angle.
Answer: Angles M and N.