The purpose of this task is primarily assessment-oriented, asking students to demonstrate knowledge of how to determine the congruency of triangles.

Includes chapters on: Basics of Geometry, Reasoning and Proof, Parallel and Perpendicular Lines, Triangles and Congruence, Relationships with Triangles, Polygons and Quadrilaterals, Similarity, Right Triangle Trigonometry, Circles, Perimeter and Area, Surface Area and Volume, Rigid Transformations.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Below is a picture of two triangles: Suppose there is a sequence of rigid motions which maps $\triangle ABC$ to $\triangle DEF$. Explain why correspond...

CK-12's Basic Geometry FlexBook is designed to present students with geometric principles in a simpler, more graphics-oriented course. Students will explore geometry at a slower pace with an emphasis placed on visual aids and approachability.

The Teacher's Edition covers tips, common errors, enrichment, differentiated instruction and problem solving for teaching CK-12's Basic Geometry Student Edition. The solution and assessment guides are available upon request.

Students engage in a competitive group relay to construct formal proofs involving triangles.New proofs can always be written to fit different curriculum and pacing.

CK-12's Geometry - Second Edition is a clear presentation of the essentials of geometry for the high school student. Topics include: Proofs, Triangles, Quadrilaterals, Similarity, Perimeter & Area, Volume, and Transformations.

CK-12's Texas Instruments Geometry Student Edition Flexbook is a useful collection of exercises intended to enrich a student's understanding of basic geometric principles.

CK-12's Texas Instruments Geometry Teachers Edition Flexbook is a useful collection of exercises intended to enrich a student's understanding of basic geometric principles.

This is course material published for a secondary Math 1 course. Authors of this work are: Scott Hendrickson, Joleigh Honey, Barbara Kuehl, Travis Lemon, Janet Sutorius and updated from the original work in 2013 in partnership with the Utah State Office of Education.

CK-12 Foundation's Middle School Math € Grade 6 Flexbook covers the fundamentals of fractions, decimals, and geometry. Also explored are units of measurement, graphing concepts, and strategies for utilizing the book's content in practical situations.

This activity is one in a series of tasks using rigid transformations of the plane to explore symmetries of classes of triangles, with this task in particular focusing on the class of equilaterial triangles. In particular, the task has students link their intuitive notions of symmetries of a triangle with statements proving that the said triangle is unmoved by applying certain rigid transformations.

This task examines some of the properties of reflections of the plane which preserve an equilateral triangle: these were introduced in ''Reflections and Isosceles Triangles'' and ''Reflection and Equilateral Triangles I''. The task gives students a chance to see the impact of these reflections on an explicit object and to see that the reflections do not always commute.

This activity is one in a series of tasks using rigid transformations of the plane to explore symmetries of classes of triangles, with this task in particular focussing on the class of isosceles triangles.

Informative text followed by images with hot spots describing rotation of an object around a point.

Definition and description of similarity with images displaying a transformation using a point of dilation and a scale factor.

This unit covers the key aspects to prove triangles are congruent. Students will learn the five triangle congruence postulates to show triangles are congruent which are SSS, SAS, ASA, AAS and HL. Additionally the students will learn about CPCTC and how it is used in showing parts of triangles are congruent. Finally the students will learn different properties of equilateral and isosceles triangles that they will be able to apply to solve different problems.

Definition of Side-Angle-Side Congruence postulate, followed by image of two triangles with hotspots and question if the triangles are congruent.