CK-12 Foundation
Ck 12: Interactive Geometry: 6.7 Applications of Similar Triangles
Learn how similar triangles have congruent corresponding angles and proportional corresponding sides.
CK-12 Foundation
Ck 12: Interactive Geometry: 6.5 Sss Triangle Similarity
Explore and understand two triangles that are similar.
CK-12 Foundation
Ck 12: Interactive Geometry: 6.4 Sas Triangle Similarity
Explore and understand triangle similarity.
Texas Instruments
Texas Instruments: Similar Triangles and Proportions
In this activity, students will investigate the relationship among the similar triangles formed when a segment is constructed parallel to one side of a triangle. They will explore the various ratios that exist between the lengths of the...
Illustrative Mathematics
Illustrative Mathematics: G Co Midpoints of Triangle Sides
The goal of this task is to use similarity transformations to relate two triangles. The triangles are obtained by taking midpoints of two sides of a given triangle. Aligns with HSG-CO.C.10.
Illustrative Mathematics
Illustrative Mathematics: G Srt Joining Two Midpoints of Sides of a Triangle
In this task, students must prove that angles and triangles are congruent and that a parallel line passes through the midpoints of two sides of the larger triangle. Aligns with G-SRT.B.4.
Texas Instruments
Texas Instruments: Similar Figures Discovery Activity
Students can use Cabri Jr. to discover two properties of similar triangles: corresponding angles are congruent and corresponding sides are proportional.
Khan Academy
Khan Academy: Solve Similar Triangles (Basic)
Given two similar triangles and some of their side lengths, find a missing side length.
Illustrative Mathematics
Illustrative Mathematics: G Srt Similar Triangles
The goal of this task is to examine similarity of triangles from the point of view of proportional sides, showing that this is sufficient to conclude that two triangles are similar. Aligns with HSG-SRT.A.2.
Khan Academy
Khan Academy: Determine Similar Triangles: Sss
Given two triangles with some of their side measures, determine whether the triangles are similar or not.
Government of Alberta
Learn Alberta: Exploring Similarity and Congruence
Begin by watching this captivating video showing how the concepts of similarity and congruence are found in road signs. Following the video [1:27], an interactive applet allows students to resize, flip, move and rotate triangles to...
Khan Academy
Khan Academy: Practice: Determine Similar Triangles: Sss
In this set of questions, students practice identifying side-side-side similarity among triangles. Includes hints.
CK-12 Foundation
Ck 12: Geometry: Unknown Measures of Similar Figures
[Free Registration/Login may be required to access all resource tools.] Find unknown side lengths in similar figures.
Illustrative Mathematics
Illustrative Mathematics: G Srt Folding a Square Into Thirds
The goal of this task is to apply knowledge about similar triangles in order to understand an origami construction: trisection of the side of a square. Aligns with G-SRT.B.5.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Homotecia Y Semejanza
In Spanish. In this interactive activity you can understand and know how to apply direct and inverse homothety to simple shapes, apply Thale's theorem, construct similar polygons and work out their related measurements and know how to...
Illustrative Mathematics
Illustrative Mathematics: G Srt Tangent Line to Two Circles
The purpose of this task is to use similar triangles and setting up a proportion in order to calculate a side length. Aligns with G-SRT.B.5.