CK-12 Foundation
Ck 12: Geometry: Hl Triangle Congruence
[Free Registration/Login may be required to access all resource tools.] In this lesson students prove two right triangles are congruent with the Hypotenuse-Leg shortcut. Students examine guided notes, review guided practice, watch...
CK-12 Foundation
Ck 12: Geometry: Similar Polygons and Scale Factors
[Free Registration/Login may be required to access all resource tools.] Apply the properties of similar polygons.
CK-12 Foundation
Ck 12: Geometry: Third Angle Theorem Grades 8 10
[Free Registration/Login may be required to access all resource tools.] Apply the Third Angle Theorem.
CK-12 Foundation
Ck 12: Algebra: Distance Formula
[Free Registration/Login may be required to access all resource tools.] This concept introduces the distance formula and uses it to prove that line segments are congruent. Students examine guided notes, review guided practice, watch...
CK-12 Foundation
Ck 12: Geometry: Congruence Statements
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to write congruence statements and use congruence statements to determine the corresponding parts of triangles. Students examine...
CK-12 Foundation
Ck 12: Geometry: Similar Polygons and Scale Factors
[Free Registration/Login may be required to access all resource tools.] This concept teaches students what similar polygons are and how to use scale factors to solve for missing information in similar polygons.
CK-12 Foundation
Ck 12: Congruent Triangles
[Free Registration/Login Required] Students explore the concept of congruent triangles by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn more about...
CK-12 Foundation
Ck 12: Congruence Statements
[Free Registration/Login Required] Students explore the concept of congruence statements by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn more about...
CK-12 Foundation
Ck 12: Geometry: Triangle Classification Grade 8
[Free Registration/Login may be required to access all resource tools.] Classifying triangles by using angle measures and side lengths.
CK-12 Foundation
Ck 12: Algebra: Evaluation of Perfect Square Roots
[Free Registration/Login may be required to access all resource tools.] Recognize and evaluate perfect square roots
CK-12 Foundation
Ck 12: Algebra: Evaluation of Square Roots
[Free Registration/Login may be required to access all resource tools.] Evaluate square roots
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.
Sophia Learning
Sophia: Similarity
This learning tutorial describes the characteristics of similar figures and how to use scale factor and proportions to determine missing side lengths. The lesson includes PowerPoint presentations and videos demonstrating how to solve...
National Council of Teachers of Mathematics
The Math Forum: Line Symmetry
This site from The Math Forum is a great site if you are looking for activities to engage your students in learning about line symmetry. Peruse this collection of activities for one or two or four that would be right for your students....
Shodor Education Foundation
Shodor Interactivate: Lesson: An Introduction to Quadrilaterals
Quadrilaterals-parallelograms, rectangles, and trapezoids-are thoroughly introduced in this lesson plan for upper elementary and middle school students. Lots of resources are linked to it to help support the teacher and students....
Oswego City School District
Regents Exam Prep Center: Congruence of Triangles
Congruent means, "same size, same shape." Find out more about this concept at this test prep site with real world examples and pictures. Hands-on classroom activity and lots of practice. Knowledge of basic algebra and geometry concepts...
Varsity Tutors
Varsity Tutors: Hotmath: Similar Figures
Find a clear explanation of similar figures. Discusses how they can be transformed through a sequence of rotations, reflections, translations, and dilations. Explanations are supported with illustrated examples.
National Institute of Educational Technologies and Teacher Training (Spain)
Ministerio De Educacion: Flecha
Can you make the second arrow the same size as the first? You will be surprised.
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.
Purple Math
Purplemath: Conventions
A "convention" is "just the way a thing is done!". This reference material lists some common conventions (notational assumptions) for geometry and trigonometry.
Math Open Reference
Math Open Reference: Congruence
A complete reference guide to congruence including congruent triangles and polygons. It provides definitions, animation, and interactive activities that enhance further explanation.
CK-12 Foundation
Ck 12: Geometry: Congruent Triangles
[Free Registration/Login may be required to access all resource tools.] In this lesson students determine whether two triangles are congruent. Students examine guided notes, review guided practice, watch instructional videos and attempt...
CK-12 Foundation
Ck 12: Geometry: Congruent Triangles
[Free Registration/Login may be required to access all resource tools.] This concept teaches students what it means for two triangles to be congruent and how to identify corresponding parts of congruent triangles. Students examine guided...
CK-12 Foundation
Ck 12: Geometry: Aa Similarity
[Free Registration/Login may be required to access all resource tools.] Use the AA Similarity Postulate to determine if triangles are similar.