triangles 83 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 
Equiangular Polygon Sums
Geometry Polygons
How to find the measure of one angle in any equiangular or regular polygon.
equiangular regular congruent triangles sum 
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 
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 
Polygons
PreAlgebra Introductory Geometry
Naming polygons, classifying triangles, and classifying quadrilaterals

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 
Finding the Slope of a Line from a Graph
Algebra Linear Equations and Their Graphs
How to find the slope of a line if given a graph.
slope change ratio fraction slope triangle 
Two Column Proofs
Geometry Triangles
How to organize a two column proof.
statement reason cpctc prove show congruent triangles 
Rotational Symmetry
Geometry Transformations
How to define rotational symmetry and identify the degree of rotational symmetry of common regular polygons.
symmetry rotation point symmetry image equilateral triangle 
Using the Pythagorean Theorem to find a Missing Leg
Geometry Pythagorean Theorem
How to use the Pythagorean Theorem to find a missing leg, given the length of the hypotenuse and a leg.
Pythagorean theorem leg hypotenuse right triangle 
Finding the Slope of a Line from a Graph
Algebra 2 Graphs of Linear Equations
How to find the slope of a line if given a graph.
slope change ratio fraction slope triangle 
Using the Pythagorean Theorem to find a Missing Leg
Trigonometry Pythagorean Theorem
How to use the Pythagorean Theorem to find a missing leg, given the length of the hypotenuse and a leg.
Pythagorean theorem leg hypotenuse right triangle 
The Tangent Function
Trigonometry Trigonometric Functions
How to define the tangent function for all angles.
tangent right triangle trigonometry the unit circle 
The Tangent Function
Precalculus Trigonometric Functions
How to define the tangent function for all angles.
tangent right triangle trigonometry the unit circle 
Trapezoid Midsegment Properties
Geometry Polygons
How to define the midsegment of a trapezoid, calculate its length, and relate it to a triangle midsegment.
midsegment trapezoid average bases midpoint 
Vertex and Diagonals
Geometry Geometry Building Blocks
How the vocabulary word vertex applies to different objects in Geometry.
vertex isosceles triangle polygon diagonal cone pyramid prism 
Flowchart Proofs
Geometry Triangles
How to outline a flowchart proof.
flowchart proof given cpctc isosceles triangle reflexive property 
Reflectional Symmetry
Geometry Transformations
How to identify and describe reflectional symmetry.
symmetry figure maps isometry mirror image square equilateral triangle 
Area of Regular Polygons
Geometry Area
How to derive the formula to calculate the area of a regular polygon.
area apothem side hexagon isosceles triangle perimeter equilateral equiangular 
Area of a Segment
Geometry Area
How to derive the area of a segment formula.
segment sector triangle area radius central angle shaded area