Curated OER
How Do You Find a Scale Factor in Similar Figures?
Three angles of one triangle are equal to the corresponding angles in another triangle. Use a ratio of corresponding sides to find the scale factor. Actually, there are two scale factor values. The instructor will explain how to get both...
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 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
How Do You Find Missing Measurements of Similar Figures Using a Proportion?
Two similar triangles have the same angles, but their legs have different lengths. This means their angles are congruent, and thusly, their corresponding sides are congruent. So there is a missing measurement that needs to be found. Set...
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: 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: 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: 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]
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: Geometry: Congruent Triangle Example 2
Demonstrates how to use triangle congruency to prove that corresponding sides of congruent triangles are congruent and then identifies other congruent parts in the overlapping triangle diagram. The proof is written in the form of a...
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: 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: Finding Scale Factors
This video tutorial demonstrates how to calculate the scale factor for two similar figures. [4:11]
Sophia Learning
Sophia: Similar Figures
Similar figures are investigated in this video lesson. [4:30] It provides detailed examples using proportional relationships. Students can check their understanding with an assessment.
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.
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: Triangles: Pythagorean Theorem Proof Using Similarity
This video shows a proof for the Pythagorean Theorem by breaking a right triangle into two similar triangles and setting up ratios of corresponding sides.
Loyola University Chicago
Math Flix: Similar Figures: Proof Using Proportions
This QuickTime movie provides an opportunity to develop the basic geometric term, similar, by checking to see if figures are proportionaly similar. As you watch and listen to the teacher and student interact it helps clarify the thinking...