West Contra Costa Unified School District
Congruent and Similar Polygons
What's similar about congruent and similar polygons? Young mathematicians first measure the side lengths and angles of given figures. They use these measurements to determine relationships between side lengths and angles of congruent and...
Willow Tree
Ratios and Proportions with Congruent and Similar Polygons
Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...
Charleston School District
Identifying Series and Determining Congruence or Similarity
Learners consider a set of questions to determine a series of transformations that will move one figure to another. Once the series is determined, the pupil then determines whether the pre-image and image are either congruent...
University of Utah
Geometry: Transformations, Congruence, and Similarity
Rigid motions are to congruence as what are to similarity? Investigate properties of rigid motions and define congruence in terms of rigid motions with the ninth chapter of a 10-part eighth grade workbook series. The...
Scholastic
Study Jams! Congruent Figures
There is more to congruency than just looking similar. Learn the difference and calculate the matching angles and sides to prove the congruence between figures. Lesson has step-by-step slides and follows with an assessment.
CK-12 Foundation
Properties of Congruence: Congruent Figures
No two resources are exactly the same, but polygons can be. Scholars match congruent figures by dragging them together in an interactive. They answer some challenge questions that justify their matches.
Mathematics Vision Project
Similarity and Right Triangle Trigonometry
Starting with similar triangles and dilation factors, this unit quickly and thoroughly progresses into the world of right triangle features and trigonometric relationships. Presented in easy-to-attack modules with copious application...
EngageNY
More About Similar Triangles
Determine whether two triangles are similar. The lesson presents opportunities for pupils to find the criterion needed to show that two triangles are similar. Scholars use the definition of similarity to find any missing side...
EngageNY
Basic Properties of Similarity
Does the symmetry and transitive property apply to similarity? The 10th segment in a series of 16 presents the class with a group of explorations. The explorations have pairs show that similarity is both symmetrical and transitive....
EngageNY
Similarity
Use the coordinate plane to show two figures are similar. The lesson incorporates congruence transformations and dilations to move a figure on to another figure. Pupils determine that if a similarity transformation exists...
CK-12 Foundation
Properties of Congruence: Polygon Party
Don't let congruent figures drag you down. Young mathematicians use an interactive to drag figures onto one another to determine if the figures are congruent.
Illustrative Mathematics
Bank Shot
Young geometers become pool sharks in this analysis of the angles and lengths of a trick shot. By using angles of incidence and reflection to develop similar triangles, learners plan the exact placement of balls to make the shot....
Charleston School District
Transformation Basics
Transformations are more than the process in which sports cars become fighting robots. Listed in terms of which transformations give congruent or similar figures, several resources provide definitions and examples of the four...
Charleston School District
Constructing Dilations
Pupils multiply the vertical and horizontal distances from the center of dilation by the scale factor. The independent practice prompts the class to analyze the relationship between the image and pre-image. The lesson is...
EngageNY
Congruence, Proof, and Constructions
This amazingly extensive unit covers a wealth of geometric ground, ranging from constructions to angle properties, triangle theorems, rigid transformations, and fundamentals of formal proofs. Each of the almost-forty lessons...
EngageNY
What Lies Behind “Same Shape”?
Develop a more precise definition of similar. The lesson begins with an informal definition of similar figures and develops the need to be more precise. The class learns about dilations and uses that knowledge to arrive at a...
Scholastic
Study Jams! Classify Quadrilaterals
Face the vertex of two-dimensional shapes and discover what each figure requires as part of its classification. With one shape per slide, learners see what makes each shape special and compare it to others with similar qualities.
CK-12 Foundation
Properties of Equality and Congruence: Justifying Algebraic Steps
No need to justify using this resource. Learners drag justifications for each step of solving an equation in an interactive. To see if they are correct, all they need to do is use a slider and the correct answers appear.
Illustrative Mathematics
Applying the Pythagorean Theorem in a Mathematical Context
Participants who use this resource will apply the Pythagorean Theorem to show whether or not the shaded triangle inscribed in a rectangle is a right triangle. Once all of the sides on the shaded triangle are found, it is important that...
Scholastic
Study Jams! Lines of Symmetry
Line up this lesson when introducing symmetry to your young mathematicians. Watch how two figures are introduced to different ways of folding and identifying whether or not they are actually symmetrical. Finish the lesson with a...
Willow Tree
Angles Formed by Transversals of Coplanar Lines
Create a strong understanding of the relationships formed when parallel lines intersect a transversal. Discuss each type of angle pair and their relationship to each other.
Charleston School District
Constructing Rotations
An instructive lesson provides the basics on how to perform rotations on the coordinate plane. The handout also covers rotating about a point other than the origin and how to perform a series of transformations.
BW Walch
Linear & Exponential Functions
Positioned inside the framework of linear and exponential functions, this lesson is more of an investigation into the effects of changing variables and constants inside an expression. The author takes familiar formulas, those for...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...