The sum of the 2 angles formed at the intersection of two straight lines is 210. Find each of the angles formed.

Given:
lines MC and DE meet at point O,
angle MOE and angle DOC – vertical angles,
angle MOE + angle DOC = 210,
Find the degree measure of the angle MOD, angle MOE, angle DOC, angle EOC -?
Decision:
1) Consider the vertical angles MOE and DOC. We know that the vertical angles are equal to each other. Then
angle MOE = angle DOC;
angle MOE = angle DOC = 210: 2;
angle MOE = angle DOC = 105;
2) Angle MOD and angle MOE are adjacent. We know that the sum of the degree measures of adjacent angles is 180 degrees.
angle MOD = 180 – 105;
angle MOD = 75 degrees;
3) angle MOD = angle EOC = 75 degrees, since they are vertical.
Answer: 105 degrees; 105 degrees; 75 degrees; 75 degrees.