Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Triangulos Semejantes
Learn how to recognize and construct similar triangles with these interactive activities.
Math Open Reference
Math Open Reference: Similar Polygons and Triangles
A complete reference guide to similar triangles and polygons. It provides definitions and interactive activities that enhance further explanation.
Other
Dans Math: Lessons: Trigonometry
College professor Dan Bach reviews basic trig concepts, including trig functions, right triangles, circles, radians, and polar coordinates. Site includes animated graphs and detailed examples.
Texas Instruments
Texas Instruments: Math Today Ballooning Inside the Box
In this activity Using the USATODAY infograph, "Ballooning inside the box", students will explore geometric relationships using similar triangles. Identifying triangles with two pairs of congruent angles to explore similarity properties...
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Semenjaza
In Spanish. Interactive activities dealing with similar triangles and polygons.
University of Cambridge
University of Cambridge: Maths and Sports: Stadium Sightline
How would you design the seating for an Olympic stadium to give spectators the best view of events? This geometry and modelling activity is designed to be accessible to both GCSE and A-level maths students (Key Stage 4 and Key Stage 5),...
Mangahigh
Mangahigh: Shape: Solve Problems With Similar Shapes
Test your knowledge of similar triangles and shapes.
CK-12 Foundation
Ck 12: Geometry: Sas Similarity
[Free Registration/Login may be required to access all resource tools.] Use the SAS Similarity Theorem to determine if triangles are similar.
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. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Determine Similar Triangles: Aa
Given two triangles with some of their angle measures, determine whether the triangles are similar or not. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems: Similarity and Proportion
Practice using your graphing calculator for similarity and proportion problems. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under each problem.
CK-12 Foundation
Ck 12: Geometry: Indirect Measurement
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to use similar triangles and proportions to find measurements indirectly. Students examine guided notes, review guided practice, watch...
CK-12 Foundation
Ck 12: Geometry: Indirect Measurement
[Free Registration/Login may be required to access all resource tools.] In this lesson students use similar triangles and proportions to find measurements indirectly. Students examine guided notes, review guided practice, watch...
CK-12 Foundation
Ck 12: Indirect Measurement
[Free Registration/Login Required] Students use similar triangles to determine the height of the base of a tree house. Click learn more to watch a video and click challenge me to answer a practice question.
CK-12 Foundation
Ck 12: Geometry: Indirect Measurement
[Free Registration/Login may be required to access all resource tools.] Recognize similarity and use similar figures to solve problems by using indirect measurement
CK-12 Foundation
Ck 12: Geometry: Parallel Lines and Transversals
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to use the Triangle Proportionality Theorem with multiple parallel lines.
CK-12 Foundation
Ck 12: Triangle Identification as Similar, Congruent, or Neither
[Free Registration/Login may be required to access all resource tools.] Determine whether triangles are similar, congruent, or neither.
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...
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Determining Triangle Similarity
Dr. Math responds to a question about how to determine if two triangles are similar. The Dr. goes into detail about the process and gives several examples that are worked out for you.
Khan Academy
Khan Academy: Solve Triangles: Angle Bisector Theorem
Use the Angle Bisector Theorem to find missing side lengths in triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Analyze Math
Analyze Math: Similar Triangle Examples
The geometry tutorial investigates similar triangles. Students learn about the definitions and theorems of similar triangles. Topics included are angle-angle, side-side-side, and side-angle-side similarity. The activity has several...
Science Struck
Science Struck: Similarity Statement in Geometry With Examples
Models how to write a similarity statement about different types of triangles and quadrilaterals.
Math Planet
Math Planet: Algebra 1: Similar Figures
Provides examples that illustrate similar triangles.
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.