OML Search

Proving Triangles are Similar

Related Topics:
More Lessons for Grade 8 Math
Math Worksheets

Examples, solutions, videos, worksheets, stories, and lessons to help Grade 8 students learn how to determine if two triangles are similar.

Triangle Similarity - AA SSS SAS & AAA Postulates
Proving Similar Triangles, Two Column Proofs
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.
Similar Triangle Proofs
Students learn that if two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar (Angle-Angle Similarity Postulate, or AA Similarity Postulate). Students also learn that the scale factor is ratio of the lengths of two corresponding sides. Students are then asked to use these concepts to determine whether given triangles are similar, and to find the missing side lengths in similar triangles.

Proving Triangles are Similar
Students learn the following theorems related to similar triangles.
Similar Triangles in Right Triangles
If an altitude is drawn from the right angle in a right triangle, three similar triangles are formed, also because of the AA shortcut.

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.
Mathway Calculator Widget

OML Search

We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.