the half angle formulas 158 videos

Polygon Angle Sum
Geometry Polygons
How to derive the formula to find the sum of angles in any polygon.
triangle angle sum diagonal polygon 
Remote Interior Angles
Geometry Triangles
How to define exterior angles and their remote interior angles and how to prove their properties.
exterior angle remote interior angle non adjacent angle 
Angles
PreAlgebra Introductory Geometry
Vocabulary of angles and how to measure an angle with a protractor

Corresponding Angles
Geometry Reasoning, Diagonals, Angles and Parallel Lines
How to define corresponding angles and their special properties.
parallel lines angles congruence 
Angle Bisectors
Geometry Geometry Building Blocks
How to label an angle bisector; how to use an angle bisector to find a missing variable.
congruent angles ray 
Duplicating an Angle
Geometry Constructions
How to duplicate an angle using a compass and straightedge.
congruent angles construction compass straightedge 
Midpoint Formula
Algebra 2 Graphs of Linear Equations
How to find the midpoint of two points.
midpoint formula 
Solving Formulas
Geometry Area
How to strategize about solving formulas for variables; how to solve the area of a rectangle formula for base and height; how to solve the area of a triangle formula for base and for height.
formulas isolating a variable rectangle area triangle area trapezoid area regular polygon area 
Exterior Angles of a Polygon
Geometry Polygons
How to find the sum of the exterior angles in a polygon and find the measure of one exterior angle in an equiangular polygon.
exterior angle sum of angles equiangular polygon 
Radian Measure of Angles
Trigonometry Trigonometric Functions
How to measure angles using degrees or radians.
angle degree measure acute angle right angle obtuse angle radian measure 
Radian Measure of Angles
Precalculus Trigonometric Functions
How to measure angles using degrees or radians.
angle degree measure acute angle right angle obtuse angle radian measure 
Angles in Semicircles and Chords to Tangents
Geometry Circles
How to prove that an angle inscribed in a semicircle is a right angle; how to solve for arcs and angles formed by a chord drawn to a point of tangency.
inscribed angle semicircle tangent chord intercepted arc 
Using the Sine and Cosine Addition Formulas to Prove Identities
Precalculus Advanced Trigonometry
How to use the sine and cosine addition formulas to prove the cofunction identities.
the cosine addition formulas the sine addition formulas 
Using the Sine and Cosine Addition Formulas to Prove Identities
Trigonometry Advanced Trigonometry
How to use the sine and cosine addition formulas to prove the cofunction identities.
the cosine addition formulas the sine addition formulas 
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 
Alternate Interior Angles
Geometry Reasoning, Diagonals, Angles and Parallel Lines
How to define alternate interior angles and their special properties.
parallel lines angles congruence interior transversal 
Alternate Exterior Angles
Geometry Reasoning, Diagonals, Angles and Parallel Lines
How to define alternate exterior angles and their special properties.
parallel lines angles congruence exterior transversal 
Triangle Angle Sum
Geometry Triangles
How to apply the triangle angle sum theorem.
triangle angle sum theorem 180 degrees 
The Angle Between Vectors
Precalculus Vectors and Parametric Equations
How to compute the angle between two vectors.
dot product angle between vectors position vectors