Basic Concept of Euclidean Geometry

What do you call a two lines that meet in a point?

• Parallel lines

• Intersecting lines

• Concurrent lines

• Perpendicular lines

A lines which all intersect at the same point.

• Parallel lines

• Intersecting line

• Concurrent lines

• Perpendicular line

It is a point in the exact middle of a given straight line segment.

• Intersection point

• Collinear point

• Midpoint

• Ray

What do you call a points that lie in the same straight lines or segment?

• Point

• Collinear point

• Line segment

• Midpoint

Types of lines which drawn in a 3-dimensional space, are both neither parallel nor perpendicular and do not intersect.

• Skew lines

• Perpendicular bisector

• Perpendicular lines

• Concurrent lines

A type of angles which share line segments and vertices are equivalent.

• Supplementary angle

• Adjacent angle

• Straight angle

• Vertical angle

An angle which measure greater than 90°.

• Right angle

• Obtuse angle

• Acute angle

• Reflex angle

A lines which may extend forever in either direction without ever interesting.

• Parallel lines

• Intersecting line

• Concurrent line

• Perpendicular line

An angle that has same vertex and share a side.

• Supplementary angle

• Adjacent angle

• Straight angle

• Vertical angle

It is considered as a axiomatic system, where all the theorems are derived from small number of simple axioms.