Lumos Video Store
This page provides a list of educational videos related to Angle and Side Relationships. You can also use this page to find sample questions, apps, worksheets, lessons , infographics and presentations related to Angle and Side Relationships.
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
Similar triangles 1
By Khan Academy
Sal reviews all the different ways we can determine that two triangles are similar. This is similar to the congruence criteria, only for similarity!
Solving problems with similar and congruent triangles
By Khan Academy
Sal uses the similarity of triangles and the congruence of others in this multi-step problem to find the area of a polygon.
Special right triangles
By Khan Academy
Showing the ratios of the sides of a 45-45-90 triangle are 1:1:sqrt(2)
Special right triangles
By Khan Academy
A few more 45-45-90 examples and an introduction to 30-60-90 triangles.
Special right triangles
By Khan Academy
Using what we know about 30-60-90 triangles to solve what at first seems to be a challenging problem
Solving similar triangles 1
By Khan Academy
Sal solves two problems where a missing side length is found by proving that triangles are similar and using this to find the measure.
Find missing angles of triangles
By Khan Academy
Sal combines what we know about isosceles triangles and parallel lines with the power of algebra to solve the angles of an isosceles triangle.
Find missing angles of triangles
By Khan Academy
Three example problems involving isosceles and equilateral triangles (partly taken from Art of Problem Solving, by Richard Rusczyk).
Find missing angles of triangles
By Khan Academy
Sal solves the following problem: The measures of two angles of an isosceles triangle are 3x+5 and x+16. Find all possible values of x.
Trigonometric functions of special angles
By Khan Academy
Sal finds the trigonometric values of���������������������������/4.
Inscribed Angles
By Wes Przybylski
This video provides a relatively quick lesson about inscribed angles and inscribed polygons. Uses diagrams to illustrate concepts.
Sine Values from Special Triangles
By outofmylaboratory
YouTube presents Sine Values from Special Triangles an educational video resources on math.
Angles: Composition Measuring
By tiorico1
The instructor uses an electronic sketchpad to demonstrate how to constucut angles. Video discusses vocabulary and symbols associated with angles ray (sides of the angle) vertex (the point where the rays start). It then goes on to use the protractor to measure an angle. It starts with where to put one line of the angle and then where and what to measure. It also instructs students which set of numbers to use on a protractor. Then examples are measured. Good video for instruction and review for any grade level.
Trigonometric Ratios of Special Angles
By AlRichards314
This video shows us how we determine the trigonometric ratios for the angles of 30 degrees, 45 degrees, and 60 degrees. Keep in mind that the ratios of the sides corresponding to these angles never change (even though the side lengths may change). That means that knowing the values for these trig ratios means you'll know them forever! They won't change!
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.
Geometry -- Lesson 4.3 -- Congruent Triangles
By MisterRutter
This geometry lesson explains congruent triangles: triangles with the same measure sides and angles.
Trigonometric Functions To Find Unknown Sides of Right Triangles, Ex 2
By PatrickJMT
Trigonometric Functions To Find Unknown Sides of Right Triangles, Ex 2. In this video, I use information about the length of the hypotenuse of a right triangle as well as a trig function to find the length of a missing side.