acute angle 97 videos

Types of Triangles
Geometry Geometry Building Blocks
How to classify a triangle based on its side lengths and angle measures.
equiangular equilateral isosceles right acute obtuse triangles 
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 
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 
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 
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 
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 
Corresponding Parts of Similar Triangles
Geometry Similarity
How to relate corresponding altitudes, medians and angle bisectors in similar triangles.
similar triangles altitude median angle bisector proportional 
ASA and AAS
Geometry Triangles
How to use the ASA and AAS shortcuts to determine the congruence of two triangles.
triangle congruence angle side angle angle angle side 
Radii to Tangents
Geometry Circles
How to define a tangent line; how to determine the angle a radius to a tangent forms.
tangent radius right angle point outside the circle perpendicular 
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 
Evaluating the Tangent Function
Trigonometry Trigonometric Functions
How to evaluate the tangent of 3*pi/4.
tangent quadrants reference angles 
Evaluating the Tangent Function
Precalculus Trigonometric Functions
How to evaluate the tangent of 3*pi/4.
tangent quadrants reference angles 
Similar Triangles in Circles and Right Triangles
Geometry Similarity
How to determine if two triangles in a circle are similar and how to prove that three similar triangles exist in a right triangle with an altitude.
similar inscribed angles intercepted arc right angle circle 
Parallelogram Properties
Geometry Polygons
How to identify all of the special properties of parallelograms and use them to solve problems.
opposite sides parallel opposite angles same side interior angles diagonals bisect consecutive angles rhombus rectangle square 
The Definitions of Sine and Cosine
Trigonometry Trigonometric Functions
How we define sine and cosine for all angle measures using the unit circle.
sine cosine right triangle definitions of sine and cosine angles in standard position unit circle definitions of sine and cosine 
The Definitions of Sine and Cosine
Precalculus Trigonometric Functions
How we define sine and cosine for all angle measures using the unit circle.
sine cosine right triangle definitions of sine and cosine angles in standard position unit circle definitions of sine and cosine 
Constructing the Incenter
Geometry Constructions
How to construct the incenter using a compass and straightedge.
point of concurrency angle bisectors equidistant 
Similar Triangles
PreAlgebra Introductory Geometry
Overview of similarity: congruent angles, proportional corresponding sides

The Tangent Function
Trigonometry Trigonometric Functions
How to define the tangent function for all angles.
tangent right triangle trigonometry the unit circle