auxiliary lines 71 videos

Line Segments
Geometry Geometry Building Blocks
How to define and label a line segment.
line endpoint points 
Constructing a Perpendicular at a Point on a Line
Geometry Constructions
How to construct a perpendicular line at a point on a line.
perpendicular point on the line construct 
Parallel and Skew Lines
Geometry Geometry Building Blocks
How to mark parallel lines, how to show lines are parallel, and how to compare skew and parallel lines.
parallel lines skew lines coplanar collinear 
Parallel and Skew Lines
Precalculus Equations of Lines, Parabolas and Circles
How to mark parallel lines, how to show lines are parallel, and how to compare skew and parallel lines.
parallel lines skew lines coplanar collinear 
Parallel Planes and Lines
Geometry Geometry Building Blocks
How to identify parallel lines, a line parallel to a plane, and two parallel planes.
parallel lines skew plane 
Parallel Planes and Lines
Precalculus Equations of Lines, Parabolas and Circles
How to identify parallel lines, a line parallel to a plane, and two parallel planes.
parallel lines skew plane 
Standard Form of a Line
Algebra 2 Graphs of Linear Equations
How to use standard form of a line.
standard form of a line 
Converse of Parallel Lines Theorem
Geometry Reasoning, Diagonals, Angles and Parallel Lines
How to take the converse of the parallel lines theorem.
parallel lines theorem transversal 
Converse of Parallel Lines Theorem
Precalculus Equations of Lines, Parabolas and Circles
How to take the converse of the parallel lines theorem.
parallel lines theorem transversal 
Lines in 3D
Precalculus Vectors and Parametric Equations
How to find the vector and parametric equations of a line when given two points on the line.
the vector equation of a line position vectors direction vector parametric equations 
Angle Inclination of a Line
Precalculus Advanced Trigonometry
How to find the angle of inclination of a line.
angle inclination horizontal lines tangent slope 
Angle Inclination of a Line
Trigonometry Advanced Trigonometry
How to find the angle of inclination of a line.
angle inclination horizontal lines tangent slope 
PointSlope Form of a Line
Algebra 2 Graphs of Linear Equations
How to use pointslope form of a line.
point slope form equation of a line 
Constructing a Perpendicular to a Line
Geometry Constructions
How to find the shortest distance between a point and a line.
construction midpoint perpendicular equidistant shortest distance to a line 
SlopeIntercept Form of a Line
Algebra 2 Graphs of Linear Equations
How to graph a line in slopeintercept form.
slope intercept y=mx+b graphing a line 
Perpendicular, Parallel and Skew Lines in Space
Precalculus Vectors and Parametric Equations
How to determine whether two lines in space are parallel or perpendicular.
perpendicular lines dot product direction vectors parallel lines scalar multiple skew lines 
The Vector Equation of a Line
Precalculus Vectors and Parametric Equations
How to write the vector equation of a line.
position vector direction vector vector addition scalar multiple vector equation line 
Lines in Polar Coordinates
Precalculus Polar Coordinates and Complex Numbers
How to find the polar equation of a line through the origin (or pole).
polar coordinates lines origin polar equation rectangular equation 
Parametrizing a Line Segment
Precalculus Vectors and Parametric Equations
How to write the parametric equations of a line segment that goes from point A to point B.
vector equation line segment parametric equations 
Proportional Segments Between Parallel Lines
Geometry Similarity
How to prove two triangles are similar using a line parallel to a base.
parallel lines triangles similar triangles proportion