triangle area 115 videos

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 
Triangle Angle Sum
Geometry Triangles
How to apply the triangle angle sum theorem.
triangle angle sum theorem 180 degrees 
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 
Pascal's Triangle
Precalculus Topics in Discrete Math
How to use Pascal's triangle.
zero product property factoring constant 
Pascal's Triangle
Algebra 2 Polynomials
How to use Pascal's triangle.
zero product property factoring constant 
Area of Trapezoids
Geometry Area
How to derive the area of a trapezoid formula using the area of a rectangle.
trapezoid parallelogram base height 
Pythagorean Theorem Proofs
Geometry Pythagorean Theorem
How to prove the Pythagorean Theorem using Algebra to show the area of the smaller square plus the area of four triangles is equal to the area of the larger square.
right triangle area of a square binomial squared area of a triangle side leg hypotenuse 
Pythagorean Theorem Proofs
Trigonometry Pythagorean Theorem
How to prove the Pythagorean Theorem using Algebra to show the area of the smaller square plus the area of four triangles is equal to the area of the larger square.
right triangle area of a square binomial squared area of a triangle side leg hypotenuse 
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 
Triangle Midsegment Properties
Geometry Polygons
How to define a triangle midsegment and describe its special properties.
midsegment triangle parallel bases midpoint third side 
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 
Iron Triangles
AP US Government AP US Government Videos
How is public policy made? Who controls the bureaucracy?
Iron triangles bureaucracy 
Approximating Area Using Rectangles
Calculus The Definite Integral
How to approximate the area under a curve using rectangles.
approximating area under a curve left hand sums right hand sums limits 
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 
Area of Kites and Rhombuses
Geometry Area
How to derive the area formula of a kite based on the rectangle formula; how to calculate the area of a rectangle using diagonal lengths.
kite area diagonals consecutive sides vertex angle non vertex angle bisect perpendicular rhombus 
306090 Triangles
Geometry Pythagorean Theorem
How to find the legs and hypotenuse in 306090 triangles when given: the short leg, the long leg, or the hypotenuse.
right triangle short leg long leg hypotenuse 
306090 Triangles
Trigonometry Pythagorean Theorem
How to find the legs and hypotenuse in 306090 triangles when given: the short leg, the long leg, or the hypotenuse.
right triangle short leg long leg hypotenuse 
Area and Perimeter of Circles
PreAlgebra Introductory Geometry
Vocabulary and formulas for the area of a circle

Constructing a Triangle Midsegment
Geometry Constructions
How to define a midsegment in a triangle.
midpoint segment median