IMPORTANT DEFINITIONS ABOUT ANGLES AND LINES

Parallels:They are lines which never intersect themselves, so all their points are equidistance.
Oblique/Skew:They are lines which are not parallels neither perpendicular.
Perpendicular:They are lines which meet forming four right angles.
Angle:It is a figure formed by two rays (sides of angle) sharing a common endpoint(vertex).
Complementary angles:They are couples of angles which sum is 90º.
Supementary angles:They are couple of anles which sum is 180º.
Adyacent angles:They are angles that share one side and the vertex.
Angle bisector:It is the line segment or ray which divides an angle into two parts equals.
Right:A right angle has 90 degrees.
Acute.An acute angle is the one that has less than 90 degrees.
Flat:A flat angle has 180 degrees.