Lines and angles are basic concepts in geometry.
- A line is a straight path that goes on forever in both directions and has no thickness.
- An angle is formed when two rays meet at a common point called the vertex.
Foundations
Basic concepts that introduce lines and angles in geometry.
- Introduction to Lines and Angles
- Lines in detail
- Types of Lines
- Points, Lines and Planes
- Line Segment
- Collinear Points
- Angles in detail
- Measuring Angles
- Angle Relationships
Types of Lines
Different kinds of lines and their properties.
- Parallel Lines
- Perpendicular Lines
- Intersecting Lines
- Transversal Lines
- Skew Lines
- Parallel vs Perpendicular vs Transverse Lines
Types of Angles
Classification of angles by measure and shape.
- Types of Angles
- Acute Angle
- Obtuse Angle
- Right Angle
- Straight Angle
- Reflex Angle
- Complete Angle
- Real-life Applications of Angles
Pairs of Angles
Special relationships are formed when two angles are connected in a geometric figure.
- Pairs of Angles
- Adjacent Angles
- Complementary Angles
- Supplementary Angles
- Linear Pair of Angles
- Vertically Opposite Angles
- Consecutive Interior Angles
- Congruent Angles
- Angle Bisector
- Perpendicular Bisector
Parallel Lines and Transversals
Angle relationships are formed when a transversal cuts parallel lines.
- Properties of Parallel Lines
- Alternate Angles
- Alternate Interior Angles
- Alternate Exterior Angles
- Corresponding Angles
- Angles Between Two Lines in 3D Space
Theorems on Lines and Angles
Important geometric theorems and rules related to lines and angles.
- Exterior Angle Theorem
- Angle Sum Property of a Triangle
- Angle Bisector Theorem
- Postulates and Theorems in Geometry
- Lines Parallel to the Same Line
Constructions
Geometric constructions using a compass and a ruler for angles and lines.