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This page provides a list of educational videos related to Angle Theorems for Triangles. You can also use this page to find sample questions, apps, worksheets, lessons , infographics and presentations related to Angle Theorems for Triangles.
Angle bisector theorem proof | Special properties and parts of triangles | Geometry | Khan Academy
By Khan Academy
In this video, we'll quickly review the angle bisector theorem, and then we'll see how it's proven. We prove it by extending a parallel line to one of the triangle's legs. That tells us information about the interior angles!
Proving Triangles are Similar - YourTeacher.com - Geometry Help
By yourteachermathhelp
Students learn the following theorems related to similar triangles. If an angle of one triangle is congruent to an angle of another triangle, and the lengths of the sides that include each angle are in proportion, then the triangles are similar (Side-Angle-Side Similarity Theorem, or SAS Similarity Theorem). If the lengths of the sides of two triangles are in proportion, then the triangles are similar (Side-Side-Side Similarity Theorem, or SSS Similarity Theorem). Students are then asked to determine whether given triangles are similar based on these theorems.
Learning Algebra | MathHelp.com
By MathHelp.com
This lesson covers the hypotenuse leg and angle angle side theorems. Students learn the third angle theorem, which states that if two angles of one triangle are congruent to two angles of another triangle, then the third angles are congruent. Students also learn the following theorems related to congruent triangles. If two angles and the non-included side of one triangle are congruent to two angles and the non-included side of another triangle, then the triangles are congruent (Angle-Angle-Side or AAS). If the hypotenuse and leg of one right triangle are congruent to the hypotenuse and leg of another right triangle, then the triangles are congruent (Hypotenuse-Leg or HL). Students are then asked to determine whether given triangles are congruent, and name the postulate or theorem that is used.
15.2 Inequalities in a Triangle (Lesson)
By AutenMath
A lesson on the inequality theorems and relationships of side length and angle measures in a triangle
Triangle Similarity - AA SSS SAS & AAA Postulates, Proving Similar Triangles, Two Column Proofs
By The Organic Chemistry Tutor
This geometry video tutorial provides a basic introduction into triangle similarity. it explains how to use two column proofs in order to prove if two triangles are similar using the mostly the AA postulates. Other triangle similarity postulates mentioned are the AAA, SSS, and SAS postulates. Theorems used in this video include the base angle theorem, theorems associated with parallel lines, alternate interior angle theorem, vertical angles, reflexive property, definition of an altitude, right angle congruence, and more. This geometry video contains plenty of examples and practice problems on triangle similarity.
Pythagorean theorem proof using similarity | Geometry | Khan Academy
By Khan Academy
Watch this video to see a proof of the Pythagorean Theorem that uses properties of similar triangles. Remember, similar triangles have congruent angles (equal angles) and proportional corresponding sides.
7.1 Triangle Application Theorems (Lesson)
By AutenMath
A lesson explaining a.) why the sum of the measures of a triangle equals 180 degrees b.) the relationship between exterior angles and remote interior angles of a triangle and c.) the midline theorem
Triangle Angle Bisector Theorem - YourTeacher.com - Math Help
By yourteachermathhelp
Skip ahead to :18 to see another sample problem worked through. This time we're using the angle bisector theorem. Don't be confused by the word "ray" here -- she means the "bisector" or "line segment." Remember: bisect = cut in half.
Commutative Property of Multiplication | MathHelp.com
By MathHelp.com
This lesson covers the properties of a rhombus. Students learn the definitions of a rectangle, a rhombus, and a square. Students also learn the following theorems. The diagonals of a rectangle are congruent. The diagonals of a rhombus are perpendicular and bisect the angles of the rhombus. The midpoint of the hypotenuse of a right triangle is equidistant from the three vertices. Students are then asked to solve problems related to these concepts using Algebra.
The converse of the Pythagorean theorem and special triangles
By MathPlanetVideos
Find the value of x in the right triangle.
Proof of Pythagorean Theorem using similar triangles
By Matt Stryker
Proof of Pythagorean Theorem using similar triangles
Pythagorean theorem 3 | Right triangles and trigonometry | Geometry | Khan Academy
By Khan Academy
This three-minute video is from Sal Khan about using the Pythagorean Theorem to solve a word problem: A carpet measures 7 feet long and has a diagonal measurement of square root of 74 feet. Find the width of the carpet Mr. Khan uses computer software for demonstration. The screen is a little 'busy' so the viewer may want to open the screen to 'full screen' to see all more clearly.
45-45-90 triangles | Right triangles and trigonometry | Geometry | Khan Academy
By Khan Academy
Video uses an electronic black board with different colored pens. Introduction to 45-45-90 Triangles, these can also be called right triangles because of the 90 degree measurement. These triangles are special because if two angles of a triangle are equal the one side they don’t share is going to be equal. This then goes on to explain Pythagorean Theorem, Side A squared + Side B squared = Side C squared, side C is the hypotenuse or the side that is shared in a triangle. The narrator goes on to explain how to solve, using square roots. This video is for middle school students.