polygons 19 videos

Polygons
PreAlgebra Introductory Geometry
Naming polygons, classifying triangles, and classifying quadrilaterals

Number of Diagonals in a Polygon
Geometry Reasoning, Diagonals, Angles and Parallel Lines
How to determine the number of diagonals in a polygon.
vertex diagonal non consecutive vertices polygon 
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 
Polygon Angle Sum
Geometry Polygons
How to derive the formula to find the sum of angles in any polygon.
triangle angle sum diagonal polygon 
Circumscribed and Inscribed Circles and Polygons
Geometry Constructions
How to define circumscribed and inscribed circles and polygons relative to each other.
vertex radius polygon inscribed circle circumscribed 
Center and Apothem of Regular Polygons
Geometry Area
How to define the apothem and center of a polygon; how to divide a regular polygon into congruent triangles.
center circumscribed circle inscribed polygon isosceles triangle regular hexagon 
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 
Equiangular Polygon Sums
Geometry Polygons
How to find the measure of one angle in any equiangular or regular polygon.
equiangular regular congruent triangles sum 
Similarity and Area Ratios
Geometry Similarity
How to convert between length and area ratios of similar polygons
polygons similar area ratios 
Surface Area of Pyramids
Geometry Area
How to calculate the surface area of any pyramid, emphasizing regular polygons as bases.
regular polygon lateral area apothem 
Properties of Similar Polygons
Geometry Similarity
How to identify if two figures are similar.
similar figures corresponding angles congruence corresponding sides proportional 
Volume of Pyramids
Geometry Volume
How to find the volume of any pyramid.
volume base area height pyramid regular polygon 
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 
Trapezoid Arch and Panel Design Problem
Geometry Polygons
How to strategize about solving a problem with trapezoidal arches.
trapezoid arch panel design interior angle equiangular polygon isosceles 
Rectangle and Square Properties
Geometry Polygons
How to define a rectangle and a square.
equiangular polygon congruent diagonals bisect regular quadrilateral angle bisectors 
Volume of Prisms
Geometry Volume
How to find the volume of any prism, right or oblique using a general formula.
volume base area height trapezoid regular polygon oblique prism 
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 
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