# Some Geometric Terms and Results

Some geometric terms and results used in terms of words.

Some Geometric Terms and Results:

• The sum of all the angles at a point is 360°.

i.e., ∠1 + ∠2 + ∠3 + ∠4 + ∠5 + ∠6 = 360° • The sum of all the angles about a point on a straight line on one side of if it is 180°.

i.e., ∠1 + ∠2 + ∠3 + ∠4 = 360° Some Important Geometric Terms Used:

1. Equal angles:

Two angles are said to be equal if they have the same degree measure. ∠MNO and ∠XYZ are equal angles of measure 90°. 2. Bisector of an Angle:

The ray which divides the given angle into two equal angles is called an angle bisector.

In the adjoining figure, the ray BD divides ∠ABC into two equal angles ∠ABD and ∠DBC

i.e., ∠ABD = ∠DBC. Perpendicular Lines:

Two lines in a plane are said to be perpendicular if they intersect in such a way that the angles formed between them are right angles. In the adjoining e, lines PQ and RS intersect at 0 such that ∠ROQ = ∠ ROP = ∠POS = ∠QOS = 90°.

Therefore, we say that PQ is perpendicular to RS, i.e., (PQ ⊥ RS). Perpendicular Bisector:

It is the line which passes through the midpoint of the given line segment and is also perpendicular to it. Here, MN is the line segment. PQ is the perpendicular bisector as ∠POM = ∠PON = 90° and MO = ON. Some geometric terms and results are explained along with the specific figure.

Lines and Angles

Fundamental Geometrical Concepts

Angles

Classification of Angles

Related Angles

Some Geometric Terms and Results

Complementary Angles

Supplementary Angles

Complementary and Supplementary Angles

Linear Pair of Angles

Vertically Opposite Angles

Parallel Lines

Transversal Line

Parallel and Transversal Lines