Mt. San Antonio Collage
Congruent Triangles Applications
Triangles are all about threes, and practicing proving postulates is a great way to get started. The first page of the learning exercise provides a brief introduction of the different properties and postulates. The remaining pages...
Curated OER
Triangle Congruence
In this triangle congruence worksheet, students review 4 triangle congruence properties and 4 examples. Students are then prompted to complete 15 problems analyzing whether two triangles are congruent and determine by which property.
EngageNY
Triangle Congruency Proofs (part 2)
Looking to challenge your students that have mastered basic triangle congruence proofs? A collection of proofs employ previously learned definitions, theorems, and properties. Pupils draw on their past experiences with proofs to...
EngageNY
Congruence Criteria for Triangles—ASA and SSS
How do you know if a pair of triangles are congruent? Use the lesson to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through transformations and...
Curated OER
Corresponding Sides and Angles of Similar Triangles
Students differentiate between corresponding sides ad angles of two triangles. In this geometry lesson, students identify the differences as well as the similarities between two triangles. They differentiate between similar and...
Flipped Math
Similar Figures
Use some similar problems to find side lengths. Pupils learn the definition of similar figures and how it relates to corresponding angles and sides. Using the definition, individuals calculate the lengths of missing sides and practice...
Curated OER
Identifying Similar Triangles
In this identifying similar triangles worksheet, 10th graders solve 6 different types of problem that include identifying and comparing similar triangles. First, they identify the three ways that determine whether two triangles are...
Illustrative Mathematics
Base and Height
It is easy to find the area of a triangle where the base and the height are given. But in this resource, it is up to your geometers to identify the base and height of the triangle. In fact, your pupils will learn that there are three...
University of Utah
Geometry: Angles, Triangles, and Distance
The Pythagorean Theorem is a staple of middle school geometry. Scholars first investigate angle relationships, both in triangles and in parallel lines with a transversal, before proving and applying the Pythagorean Theorem.
EngageNY
Triangle Congruency Proofs (part 1)
Can they put it all together? Ninth graders apply what they know about proofs and triangle congruence to complete these proofs. These proofs go beyond the basic triangle congruence proofs and use various properties, theorems, and...
Curated OER
Exploring Characteristics Needed to Prove Two Trianlges Congruent
Tenth graders explore congruent triangles. In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles congruent. The lesson combines dry erase board activities and the use of technology.
Inside Mathematics
Rhombuses
Just what does it take to show two rhombuses are similar? The assessment task asks pupils to develop an argument to show that given quadrilaterals are rhombuses. Class members also use their knowledge of similar triangles to show two...
Curated OER
When Does SSA Work to Determine Triangle Congruence?
Your learners will make good use of the Socratic method in a collaborative task that begins with an assumed solution and ends with deeper understanding of the idea of determining two triangles congruent.
EngageNY
Modeling Using Similarity
How do you find the lengths of items that cannot be directly measured? The 13th installment in a series of 16 has pupils use the similarity content learned in an earlier resource to solve real-world problems. Class members determine...
Curated OER
Exploring Similar Figures
For this similar figures worksheet, 10th graders solve and measure 10 different angles that are similar. First, they determine which angel corresponds to each given angle. Then, students determine the scale factor of a particular...
Curated OER
Angular Size and Similar Triangles
In this angular size and similar triangles worksheet, students use the properties of similar triangles and the ratios of sides to solve for unknowns in given diagrams.
Curated OER
The Truth About Triangles And Proofs
Students engage in a lesson plan that is about the classification of triangles and the mathematical proofs involved in working with them. They work on a variety of problems that are created by the teacher with the focus upon the...
Curated OER
Indirect Measurement with Similar Triangles
Students use similar triangles to find missing heights. In this using similar triangles to find missing heights instructional activity, students use proportions to find the heights of missing side lengths. Students find the height of...
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 using the SSS,...
Illustrative Mathematics
Placing a Fire Hydrant
Triangle centers and the segments that create them easily become an exercise in memorization, without the help of engaging applications like this lesson. Here the class investigates the measure of center that is equidistant to the three...
Curated OER
Chapter 5 Final Review Extra Problems. Triangles
In this triangles worksheet, learners identify the median, altitude, segment, angle bisector, perpendicular bisector and triangle midsegment of triangles. They find the perimeter of triangles. This three-page worksheet contains 8...
Curated OER
Finding Areas of Triangles, Rectangles, and Circles
Learners find the areas of geometric shapes. In this geometry activity students find and measure the sides, perimeters, and areas of quadrilaterals, triangles, and circles. Learners relate the measures to the others by using formulas.
Curated OER
Triangle Classificaition with Geometer's Sketchpad.
Students use Geometer's Sketchpad to draw triangles and explore the classificaiton of each using the mearsures of interior angles and the lengths of the sides.
Curated OER
Similar Figures
In this similar figures worksheet, students identify the meaning of similar, corresponding sides, and congruent. They use proportions to find the length of a missing side. Students dilate given figures according to a scale factor. ...