EngageNY
Construct and Apply a Sequence of Rigid Motions
Breaking the rules is one thing, proving it is another! Learners expand on their previous understanding of congruence and apply a mathematical definition to transformations. They perform and identify a sequence of transformations and use...
EngageNY
Unique Triangles—Two Sides and a Non-Included Angle
Construct an understanding of triangle congruence through a visual analysis. Young scholars find that given two sides and a non-included angle, sometimes two possible triangles are produced. Their analysis shows that if the non-included...
EngageNY
The Angle-Angle (AA) Criterion for Two Triangles to Be Similar
What do you need to prove triangles are similar? Learners answer this question through a construction exploration. Once they establish the criteria, they use the congruence and proportionality properties of similar objects to find...
Math Mammoth
Construct Line Segments and Angles
In this math worksheet, learners are asked to used a compass and straight edge to construct copies of shapes, angles and line segments.
Curated OER
Congruent Triangles
Students explore the concept of congruent triangles. In this congruent triangles lesson, students use Cabri Jr. to construct two congruent triangles using circles. Students determine if the two triangles are congruent by...
Curated OER
Angle Exploration and Classification
Students compare and contrast angles and identify them as acute, obtuse, right, or straight angles. They create rays and angles using uncooked spaghetti, read and discuss key vocabulary terms, and complete a variety of geometry worksheets.
Curated OER
Hands On: Construct Triangles and Rectangles
In this congruent triangles and rectangles worksheet, students solve 6 word problems where they identify whether triangles and rectangles are congruent, and construct triangles. Students must explain their reasoning and prove each answer.
Mathematics Vision Project
Module 6: Congruence, Construction, and Proof
Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This...
Curated OER
Angles
Learners measure angles using a protractor. In this geometry lesson plan, students solve for the missing angles using equations set to the theorem of triangles. They measure missing angles through construction and identify congruent angles.
Texas Instruments
Copying an Angle
High schoolers will investigate geometric construction in this geometry lesson. Your pupils can explore the basic construction of copying an angle, using the constructions tools of Cabri Jr.
Curated OER
Transformations in the Coordinate Plane
Your learners connect the new concepts of transformations in the coordinate plane to their previous knowledge using the solid vocabulary development in this unit. Like a foreign language, mathematics has its own set of vocabulary terms...
Curated OER
Congruent and Similar figures
Eighth graders explore congruent and similar figures. In this eighth grade geometry lesson, 8th graders use geoboards to create congruent and similar figures and explore the relationships between the sides and angles.
Curated OER
Angles And Triangles
Seventh graders participate in a lesson that is focused upon the concepts of classifying different angles and triangles. They practice classifying triangles according to its kind that includes types of angles, congruence, and vertices....
Curated OER
Triangle Congruence
Students use web applet to create congruent triangles. For this geometry lesson, students differentiate between congruent and similar. They create shapes online and drag those shapes around to create visuals of triangles.
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...
Illustrative Mathematics
Right Triangles Inscribed in Circles I
One of the basic properties of inscribed angles gets a triangle proof treatment in a short but detailed exercise. Leading directions take the learner through identifying characteristics of a circle and how they relate to angles and...
EngageNY
Rotations
Searching for a detailed lesson to assist in describing rotations while keeping the class attentive? Individuals manipulate rotations in this application-based lesson depending on each parameter. They construct models depending on the...
Curated OER
Measuring Angles
In this measuring angles learning exercise, 10th graders solve and complete 8 various types of problems. First, they use a protractor to find the measure of each angle shown. Then, students find the missing angle measures. They also...
Curated OER
Proving Triangles Congruent
Students examine Triangle Congruency. In this measurement comparison lesson, students use inductive, deductive and analytical thinking skills to prove triangle congruency. Students analyze and record their findings on activity worksheets.
Curated OER
Congruent Triangles Postulates
Students discover three lettered postulates that prove triangles congruent.
Curated OER
Triangles & Congruence, Proportions & Similarity, Right Triangle & Trigonometry
Students are introduced to the topic of congruence and proportions in Geometry. Using technology, they construct and validate the properties of various geometric figures and identify whether it is congruent or proportion to the objects...
Illustrative Mathematics
Similar Triangles
Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...
Curated OER
Triangles
In this triangles activity, 10th graders solve 3 extensive informal geometry problems that involve triangles. First, they sketch a triangle, selecting 3 of the sides and constructing 3 midpoints. Students then draw each of 3 medians by...
Texas Instruments
Construction Regular Polygons
Learners investigate the process necessary to construct regular polygons. They explore the degree measures of the angles in a regular polygon. Using this information and technology in the form of Cabri Jr., your pupils will construct...