CK-12 Foundation
Corresponding Angles: Lesson
Take a parallel view of correspondence. The resource, part of a playlist on basic geometry, introduces the corresponding angle postulate. By first identifying corresponding angles, the video highlights the relationship between the angle...
Mathed Up!
Angles: Parallel Lines
Viewers are presented with seven problems with parallel lines and angle relationships and must use the given information to find the measures of specific angles. To finish, they explain their process in finding the measures in the...
Khan Academy
Angles (Part 3), Angles and Intersecting Lines, Geometry
As preparation for the angle game, a geometry video covers the concepts of parallel lines, transversals, slope, opposite angles,, and corresponding angles. It is the third part of a series detailing the rules and laws regarding angles.
Curated OER
How Do You Find a Value for x that Makes Two Lines Parallel?
So you have a transversal line intersecting two parallel lines and you are looking for a value that would make two corresponding angles congruent. You have all the information needed to write an equation to find the value. So write that...
Curated OER
How Do You Find a Value for x that Makes Two Lines Parallel?
So you have a transversal line intersecting two parallel lines and you are looking for a value that would make two corresponding angles congruent. You have all the information needed to write an equation to find the value. So write that...
Socratica
Parallel Lines and Transversals
Eight is the lucky number of angles when a line crosses two parallel lines. Scholars watch a concise video in the Socratica Geometry series to learn about angles made by parallel lines and a transversal. Using corresponding and vertical...
Curated OER
How Do You Find Missing Measurements of Similar Figures Using a Scale Factor?
Similar figures have corresponding sides and corresponding angles. With this in mind, missing values can be found by using a scale factor. Not sure how to do that? Watch this video as the instructor illustrates how to set up the known...
Curated OER
How Do You Find Missing Angles in a Transversal Diagram?
Parallel lines with a transversal and one given value, find the value of the other seven angles. There are many geometric terms about angles and lines to know the meaning of and understand their relationship to each other. Understanding...
Curated OER
How Do You Identify Corresponding Parts in Congruent Triangles?
Congruent, corresponding, congruent corresponding. If two figures are congruent, then their corresponding sides and corresponding angles are congruent. Is this to be believed? Watch this video and see if the proof is in the pudding.
Curated OER
What is a Transversal?
There are two parallel lines intersected by one straight line, what's that one line called? A transversal. There are a few more things to know about transversal lines and the angles they create. What are vertical angles? Are they...
Khan Academy
Khan Academy: Geometry: Similar Triangles
Explains how to determine unknown side lengths of similar triangles by identifying corresponding sides and angles ans setting up proportions. The first example is a continuation from the video "Similar Triangles." Practice problems...
Khan Academy
Khan Academy: Applications of Similar Triangles
Explains how to solve a given word problem that involves similar triangles. The problem requires that two unknown side lengths be determined. [5:34]
Khan Academy
Khan Academy: Geometry: Similar Triangles
Explains what it means for two triangles to be similar. Diagram of similar triangles is created with two parallel lines cut by two transversals. [9:34]
Khan Academy
Khan Academy: Geometry: Challenging Similarity Problem
Explains how to determine unknown side lengths in a complex diagram that involves similar triangles. [9:53]
Khan Academy
Khan Academy: Geometry: Corresponding Angle Equivalence Implies Parallel Lines
Proof by contradiction that if two lines cut by a transversal create congruent corresponding angles then the lines are parallel. [5:18]
Khan Academy
Khan Academy: Geometry: Finding Area Using Similarity and Congruence
Explains how to determine the area of a pentagonal shaded region in a triangle. The triangle that is broken into multiple similar and congruent triangles. [10:07]
Khan Academy
Khan Academy: Geometry: Angle Game (Part 2)
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem. Continuation of Angle Game video. [9:49]
Khan Academy
Khan Academy: Geometry: The Angle Game
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem. [9:01]
Khan Academy
Khan Academy: Geometry: Similar Example Problems
Explains how to identify and use similar triangles in order to determine unknown side lengths in two given diagrams. Each diagram also applies knowledge of angles formed when parallel lines are cut by a transversal. [7:37]
Khan Academy
Khan Academy: Geometry: Similarity Example Where Same Side Plays Different Roles
Explains how to determine unknown side lengths in a diagram that involves similar triangles where the two triangles share a side and the shared side corresponds to two different sides in each triangle. [6:05]
Khan Academy
Khan Academy: Geometry: Proof Sum of Measures of Angles in a Triangle Are 180
Proof that the sum of the angles in a triangle is 180 using the relationship of angles formed when parallel lines are cut by a transversal. This video also appears in the Geometry: Triangles strand. [6:31]
Khan Academy
Khan Academy: Geometry: Figuring Out All Angles for Congruent Triangles Example
Explains how to use given triangle congruency statements to determine the unknown measures of all angles in a diagram where one large triangle is divided into three congruent triangles. [4:35]
Khan Academy
Khan Academy: Geometry: Congruent Parts of Iscosceles Triangles
Proof that if the legs of an isosceles triangle are congruent then the base angles are congruent and vice versa using triangle congruency postulates. The proof is written as a two-column proof. [9:03]
Khan Academy
Khan Academy: Geometry: Similar Triangle Basics
Explains the difference between congruent triangles and similar triangles. Introduces the idea of scale factors. [9:17]