same side interior angles 123 videos

SSS and SAS
Geometry Triangles
How to use the SAS and SSS shortcuts to determine the congruence of two triangles.
triangle congruence side side side side angle side 
Cyclic Quadrilaterals and Parallel Lines in Circles
Geometry Circles
How to prove that opposite angles in a cyclic quadrilateral are congruent; how to prove that parallel lines create congruent arcs in a circle.
inscribed angles cyclic quadrilaterals parallel lines alternate interior angles 
Other Forms of the Cosine DoubleAngle Formula
Trigonometry Advanced Trigonometry
How to derive two more cosine doubleangle formulas.
the Pythagorean identity the cosine double angle formulas 
Other Forms of the Cosine DoubleAngle Formula
Precalculus Advanced Trigonometry
How to derive two more cosine doubleangle formulas.
the Pythagorean identity the cosine double angle formulas 
Constructing an Angle Bisector
Geometry Constructions
How to define and construct an angle bisector.
construction perpendicular equidistant shortest distance to a line bisector 
The Angle Between Planes
Precalculus Vectors and Parametric Equations
How to find the angle between planes, and how to determine if two planes are parallel or perpendicular.
normal vector the angle between planes perpendicular planes dot product scalar multiple parallel planes 
Special Isosceles Triangle Properties
Geometry Triangles
How to identify a segment from the vertex angle in an isosceles triangle to the opposite side.
isosceles triangle angle bisector altitude median 
Solving Exponential Equations with the Different Bases
Algebra 2 Inverse, Exponential and Logarithmic Functions
Solving an exponential equation by taking the log of both sides.
exponential function log of both sides 
Solving Exponential Equations with the Different Bases
Precalculus Exponential and Logarithmic Functions
Solving an exponential equation by taking the log of both sides.
exponential function log of both sides 
Isosceles Triangles
Geometry Triangles
How to define isosceles triangles, their components and how to determine their properties.
vertex angle leg base base angle converse remote interior angles 
Limits: A Graphical Approach
Calculus Limits and Continuity
How to determine onesided and twosided limits from the graph of a function.
one sided limits two sided limits limit does not exist piecewise functions left hand limit right hand limit graph graphical approach 
Similar Triangles
PreAlgebra Introductory Geometry
Overview of similarity: congruent angles, proportional corresponding sides

Using a Protractor
Geometry Geometry Building Blocks
How to use a protractor to measure an angle.
protractor angle acute obtuse right 
Applied Linear Equations: Geometry Problem
Algebra 2 Linear Equations
How to find the angles of a triangle by creating a linear equation.
word problem angle measure 
Applied Linear Equations: Geometry Problem
Precalculus Linear Equations and Inequalities
How to find the angles of a triangle by creating a linear equation.
word problem angle measure 
Trapezoid Properties
Geometry Polygons
How to identify a trapezoid and its special properties.
parallel sides isosceles trapezoid base angles base 
Evaluating Sine and Cosine at Other Special Angles
Trigonometry Trigonometric Functions
How to measure the sine and cosine of 150.
sine cosine unit circle definitions of sine and cosine angles in standard position reference angles 
Evaluating Sine and Cosine at Other Special Angles
Precalculus Trigonometric Functions
How to measure the sine and cosine of 150.
sine cosine unit circle definitions of sine and cosine angles in standard position reference angles 
Evaluating Sine and Cosine at Special Acute Angles
Trigonometry Trigonometric Functions
How do we measure sine and cosine of pi/4?
sine cosine unit circle definitions of sine and cosine angles in standard position 
Evaluating Sine and Cosine at Special Acute Angles
Precalculus Trigonometric Functions
How do we measure sine and cosine of pi/4?
sine cosine unit circle definitions of sine and cosine angles in standard position