Khan Academy
Khan Academy: Geometry: Congruent Triangles and Sss
In this video tutorial [11:29], the instructor explains how to use triangle congruence to identify measures of corresponding sides and angles in triangles. Defines side-side-side (SSS) postulate. Practice problems available.
Khan Academy
Khan Academy: Triangles: 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.
Khan Academy
Khan Academy: Sal's Old Angle Videos: Angle Game (Part 2)
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem.
Khan Academy
Khan Academy: Sal's Old Angle Videos: The Angle Game
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem.
Khan Academy
Khan Academy: 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.
Sophia Learning
Sophia: Pre Algebra: Indirect Measurement
Indirect measurement using shadows and proportions is explored in this video lesson. The tutorial includes a very detailed example of the concept.
Sophia Learning
Sophia: Using Smiliarity to Identify Missing Information
Find unknown information about similar figures by using similar figures. Assess learning with a quiz.
Khan Academy
Khan Academy: Triangles: Proof Sum of Measures of Angles in a Triangle Are 180
Video proving that the sum of the measures of the angles in a triangle are 180.
Khan Academy
Khan Academy: Triangles: Intro to Triangle Similarity
Explains what it means for two triangles to be similar. Diagram of similar triangles is created with two parallel lines cut by two transversals.
Khan Academy
Khan Academy: Triangles: Similarity Example Problems
Explains how to identify and use similar triangles in order to determine unknown side lengths in two given diagrams.
Virtual Nerd
Virtual Nerd: How Do You Find Missing Angles in a Transversal Diagram?
Take a look at this tutorial to see how to find all the missing angle measurements by identifying vertical, corresponding, adjacent, and alternate exterior angles. [4:43]
Khan Academy
Khan Academy: Angles Formed Between Transversals and Parallel Lines
This video explains the relationship between the measures of angles formed when parallel lines are cut by a transversal.
Khan Academy
Khan Academy: Angles (Part 3)
Identifies and defines the types of angles formed by parallel lines cut by a transversal and the relationship of their measures.
Khan Academy
Khan Academy: Geometry: Angles of Parallel Lines 2
Explains how to determine the measures of all the angles formed when parallel lines are cut by a transversal based on the measure of one angle. Explains how to use corresponding congruent angles to determine if lines cut by a transversal...
Khan Academy
Khan Academy: Triangles: Congruent Triangles and Sss
This video tutorial explains how to use triangle congruence to identify measures of corresponding sides and angles in triangles. Defines side-side-side (SSS) postulate.
Khan Academy
Khan Academy: Geometry: Angles Formed Between Transversals and Parallel Lines
Explains the relationship between the measures of angles formed when parallel lines are cut by a transversal based on relationships of corresponding, vertical, and supplementary angles. [7:53]
Khan Academy
Khan Academy: Geometry: Angles Formed by Parallel Lines and Transversals
Identifies which angles are congruent when parallel lines are cut by a transversal. [7:07]
Khan Academy
Khan Academy: Geometry: Angles (Part 3)
Identifies and defines the types of angles formed by parallel lines cut by a transversal and the relationship of their measures. Discusses Triangle Sum Theorem. [9:48]
Khan Academy
Khan Academy: Parallel Lines & Corresponding Angles Proof
Proof by contradiction that corresponding angle equivalence implies parallel lines.
Sophia Learning
Sophia: Corresponding Angles Converse: Lesson 6
This lesson [5:22] will demonstrate how to prove lines parallel with the converse of the corresponding angles postulate. It is 6 of 6 in the series titled "Corresponding Angles Converse."
Sophia Learning
Sophia: Corresponding Angles Converse: Lesson 1
This lesson will demonstrate how to prove lines parallel with the converse of the corresponding angles postulate. It is 1 of 6 in the series titled "Corresponding Angles Converse." [2:37]
Sophia Learning
Sophia: Corresponding Angles
From this lesson, you'll see that that when a transversal crosses two parallel lines, corresponding angles are congruent.
Sophia Learning
Sophia: Corresponding Angles: Lesson 2
From this lesson, you'll see that that when a transversal crosses two parallel lines, corresponding angles are congruent. It is 2 of 8 in the series titled "Corresponding Angles." [2:09]
Sophia Learning
Sophia: Corresponding Angles: Lesson 3
From this lesson, you'll see that that when a transversal crosses two parallel lines, corresponding angles are congruent. It is 3 of 8 in the series titled "Corresponding Angles." [2:09]