180 degrees pair of angles are complementary if the sum of their measures is 90 degrees.
If the two complementary angles are adjacent (i.e. have a common vertex and share just oneside) their non-shared sides form a right angle.
In Euclidean geometry, the two acute angles in a right triangle are complementary, because the sum of internal angles of a triangle is 180 degrees,and the right angle itself accounts for ninety degrees.
The adjective complementary is from Latin complementum,
associated with the verb complere, "to fill up". An acute angle is "filled up" by itscomplement to form a right angle.
Supplementary angles are pairs of angles whose measures add up to 180 degrees. The angles do not have to share a side. If the twosupplementary angles are adjacent (i.e. have a common vertex and share just one side), their non-shared sides form a line. The supplement of an angle of 135 degrees is an angle of 45 degrees. The supplement ofan angle of x degrees is an angle of 180 − x degrees. Supplementary angles do not have to be on the same line, and can be separated in space. For example, adjacent angles of a parallelogram aresupplementary.
Called conjugate angles two angles whose measures add up to 360 ° (deg).
Two angles conjugated with coincident vertices will have their common sides.
Parallel lines are coplanar lines that do not intersect. There are two other kinds of lines you need to know about. One is skew lines, which are lines that do not intersect and that are ondifferent planes. Intersecting lines are lines that have a point in common.
* The lines that are drawn at an angle to the horizon are called Oblique Lines.
In geometry,two lines or planes (or a line and a plane) are considered perpendicular (or orthogonal) to each other if they form congruent adjacent angles (a T-shape). The term may be used as a noun or...