Start by using basic angle rules. The sum of angles in a triangle is 180 degrees. The sum of angles on a straight line is 180 degrees. The sum of angles around a point is 360 degrees. In a quadrilateral, the total of all interior angles is 360 degrees.
If parallel lines are involved, remember that alternate angles are equal, corresponding angles are equal, and interior angles on the same side add up to 180 degrees.




