SubArea: Angles, arcs and sectorsLevel: BProject ID: 1003055104Source Problem: 2010007207Accepted: 1Clonable: 1Easy: 1The measures of given angles belong to the set M: M={120∘+k360∘}, k∈{−1;0;1}. Determine their arithmetic mean.120∘420∘−120∘−420∘