triangle area 115 videos

454590 Triangles
Geometry Pythagorean Theorem
How to find the length of a leg or hypotenuse in a 454590 triangle using the Pythagorean Theorem.
isosceles right triangle leg hypotenuse Pythagorean theorem square root 
454590 Triangles
Trigonometry Pythagorean Theorem
How to find the length of a leg or hypotenuse in a 454590 triangle using the Pythagorean Theorem.
isosceles right triangle leg hypotenuse Pythagorean theorem square root 
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 
Area With the Cross Product
Precalculus Systems of Linear Equations and Matrices
How to show that the magnitude of the cross product of two vectors gives the area of the parallelogram determined by those two vectors.
cross product magnitude of vectors dot product angle between vectors area parallelogram 
Triangle Side Inequalities
Geometry Triangles
How to determine the triangle side inequalities.
shortest distance side length inequalities 
Area and Perimeter of Rectangles
PreAlgebra Introductory Geometry
Overview of area and perimeter formulas for parallelograms and rectangles

Volume and Surface Area
PreAlgebra Introductory Geometry
Vocabulary and formulas for surface area and volume of common solids

Triangle Side and Angle Inequalities
Geometry Triangles
How to determine the relationship between the side inequalities and angle inequalities in a triangle.
angles smallest to largest sides smallest to largest 
Similar Triangles
PreAlgebra Introductory Geometry
Overview of similarity: congruent angles, proportional corresponding sides

HL
Geometry Triangles
How to use the hypotenuse leg shortcut to determine the congruence of right triangles.
hypotenuse leg triangle congruence right triangles 
Proportional Segments Between Parallel Lines
Geometry Similarity
How to prove two triangles are similar using a line parallel to a base.
parallel lines triangles similar triangles proportion 
Indirect Measurement
Geometry Similarity
How to use similar triangles to measure the height of objects.
indirect measurement similar triangles measurement 
Converse of the Pythagorean Theorem
Geometry Pythagorean Theorem
How to use the converse of the Pythagorean Theorem to determine if a triangle is a right triangle, how to use Pythagorean triples to memorize the lengths of certain right triangles.
right triangle leg hypotenuse converse Pythagorean triples 
Converse of the Pythagorean Theorem
Trigonometry Pythagorean Theorem
How to use the converse of the Pythagorean Theorem to determine if a triangle is a right triangle, how to use Pythagorean triples to memorize the lengths of certain right triangles.
right triangle leg hypotenuse converse Pythagorean triples 
Similarity and Volume Ratios
Geometry Similarity
How to identify if two solids are similar and how to convert 1D ratios to surface area and volume ratios.
similarity volume ratios surface area 
Similarity Shortcuts
Geometry Similarity
How to determine if two triangles are similar using a shortcut.
similar triangles AA SAS SSS proportion congruence 
CPCTC
Geometry Triangles
How to use the principle that corresponding parts of congruent triangles are congruent, or CPCTC.
corresponding parts or congruent triangles proofs 
Inverse Trigonometric Functions
Geometry Basic Trigonometry
How to use inverse trig functions to find angles in right triangles.
trigonometry right triangle inverse sine cosine tangent 
Inverse Trigonometric Functions
Trigonometry Basic Trigonometry
How to use inverse trig functions to find angles in right triangles.
trigonometry right triangle inverse sine cosine tangent