Curated OER
Concurrent Lines in Triangles
Students explore the concept of concurrent lines in triangles. In this concurrent lines in triangles lesson, students work in groups to investigate properties of concurrent lines in acute, right, and obtuse triangles. Students use a...
Curated OER
Similar Triangles
In this similar triangles worksheet, 10th graders solve and complete 10 different problems related to determining the sides of similar triangles. First, they write three equal ratios to show the corresponding sides that are proportional....
Curated OER
The Triangles Problem
In this geometry worksheet, 10th graders explain how two triangles can have 5 parts of the other triangle and still not be congruent. This is a word problem with an answer key.
Curated OER
Corresponding Parts of Similar Triangles
Here is a lesson that has learners take a look at corresponding parts of similar triangles, ratios of similarity, reductions and enlargements. They'll manipulate the scale factor (r) to observe the changes in similar triangles and then...
Curated OER
Eighteen SSS or SAS Triangle Congruence Problems
In this triangle congruence activity, students state if triangles are congruent and if the congruence is based on side, side, side or the side, angle, side theorems in eighteen problems. The solutions are found on the last two pages.
Curated OER
Congruent Containers
In this congruency activity, students find congruency in everyday packaging on everyday items and answer questions about them. Students answer 4 questions.
Curated OER
Geometry and Measurement Pre-Test
Use this comprehensive pre-instruction assessment tool to focus your teaching where your class needs it most. Multiple choice questions assess your budding geometers' conceptual and vocabulary knowledge, but they do not solve any...
EngageNY
Are All Parabolas Similar?
Congruence and similarity apply to functions as well as polygons. Learners examine the effects of transformations on the shape of parabolas. They determine the transformation(s) that produce similar and congruent functions.
Mathematics Assessment Project
College and Career Readiness Mathematics Test A2
A six-page evaluation covers material included in algebra, geometry, and algebra II. Applied word problems are mixed in with short answer questions. It also provides questions on mathematical reasoning.
Curated OER
Triangles & Congruence, Proportions & Similarity, Right Triangle & Trigonometry
High schoolers 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...
Curated OER
Equilateral Triangles
Students examine the attribute of equilateral triangles. In this equilateral triangle lesson, students examine a number of paper triangles to determine how they are classified. They determine how triangles are depicted in Navajo rugs.
Curated OER
Similar Triangles
Ninth graders find the height of every day objects using techniques learned through postulates that allow triangles in a problem to be similar. They calculate the length of a missing side and solve proportions.
Curated OER
Triangles in Architecture
Learners find triangles in the real world. In this geometry lesson, students analyze and identify properties of two and three-dimensional objects. They differentiate between similarity and congruence.
Curated OER
The Isosceles Triangle Problem
In this geometry activity, 10th graders solve a problem involving an isosceles triangle. The problem appears to be deceptively easy, but instead requires the use of trigonometry to arrive at a correct solution. The one page activity...
Curated OER
NON-EUCLIDEAN GEOMETRY.
Students study relationships between angles, side lengths, perimeters, areas and volumes of similar objects. In this lesson students also create and critique inductive and deductive arguments concerning congruency, similarity and the...
Curated OER
Isosceles Triangles
Students investigate triangles. In this shapes geometry lesson, students define and state the attributes for equilateral, scalene, and isosceles triangles. Students locate the prefix "tri" in a variety of words and make connections with...
Curated OER
Geometry
Students are introduced to the basics of Geometry. Using cutout shapes, they identify whether they are polygons by using the properties of polygons. They practice drawing shapes they are going to be using on an everyday basis and...
Curated OER
Triangle Attributes and Measures
Seventh graders explore the concept of triangles. In this triangles lesson, 7th graders sort triangles according to various attributes such as acute, obtuse, isosceles, or equilateral. Students find the area and perimeter of triangles.
Futures Channel
Folding Circles
Students investigate properties of circles. In this geometry lesson, students differentiate between similarity and congruence as they observe polygons. They investigate properties of two and three dimensional shape.
Curated OER
Slides, Flips. Turns......It's All On A Memory Book Page
Fourth graders use tangram sets to investigate the congruence of shapes. They use congruent shapes to demonstrate the properties of slides, flips, and turns. They complete a math journal entry that describes and illustrates each concept.
Curated OER
Euclidean Direct Proofs
Learning how to prove theorems in geometry can be challenging. This resource explains what a proof is, and the different styles for proofs. It also contains links to web-based practice problems that help guide learners though example...
Illustrative Mathematics
Reflections and Isosceles Triangles
Geometers explore symmetries of isosceles triangles by using rigid transformations of the plane. They complete four tasks, including congruence proofs, which illustrate the relationship between congruence and rigid transformations. The...
Curated OER
The Centroid of a Triangle
Young scholars familiarize themselves with the construct and measure menus. They demonstrate how to use the Sketchpad Calculator. They draw a triangle and construct the centroid. They shade in each of the small triangles and measure the...
Curated OER
Quilting Geometry
Study geometry through the concept of quilt design. High schoolers examine the geometric shapes in various quilts and then create their own quilts using geometric shapes that fit together. In the end, they write a paragraph to describe...