Worksheet
Curated OER

Triangle worksheets

For Students 10th
In this geometry worksheet, 10th graders explore triangle properties, including the sum of the measures of the angles of a triangle, the triangle inequalities, properties of isosceles triangles, properties of congruent triangles, and...
Worksheet
Curated OER

Parts of Similar Triangles

For Students 10th
In this parts of similar triangles worksheet, 10th graders solve 6 different problems related to determining the value of various parts of similar triangles. First, they find the value of x in the 2 figures shown. Then, students find the...
Worksheet
Curated OER

Congruence: Practice

For Students 4th - 6th
In this congruence worksheet, learners trace figures, measure sides and angles, mark congruent sides and angles, then use a given diagram to answer questions and explain reasoning. Students also answer 2 test prep questions. Houghton...
Worksheet
Curated OER

Properties of Geometry

For Students 10th
In this properties of geometry learning exercise, 10th graders solve and complete 12 different problems that include various theorems. First, they draw a figure that illustrates the SAS inequality property. Then, students prove that two...
Worksheet
Curated OER

The Isosceles Triangle Problem

For Students 10th
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...
Lesson Plan
Curated OER

Similar Triangles

For Teachers 9th
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.
Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles worksheet, 10th graders solve 10 different problems that include determining the means proportionally in each right triangle. First, they use the given information to determine the measure of each line segment....
Lesson Plan
Curated OER

Triangles in Architecture

For Teachers 10th - 12th
Students find triangles in the real world. In this geometry lesson plan, students analyze and identify properties of two and three-dimensional objects. They differentiate between similarity and congruence.
Lesson Plan
Curated OER

Angles And Triangles

For Teachers 7th
Seventh graders participate in a activity 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....
Lesson Plan
Curated OER

Similar Triangles

For Teachers 9th - 10th
Students differentiate between similar and congruent triangles. For this geometry lesson, students identify the missing side and angle of a triangle. They identify the different ratio and proportion of the sides of a triangle.
Lesson Plan
Curated OER

Isosceles Triangles

For Teachers 9th - 10th
Students identify the properties of an isosceles triangle. In this geometry lesson plan, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.
Worksheet
Curated OER

Similar Triangles

For Students 10th
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....
Worksheet
Curated OER

Proofs

For Students 8th - 11th
In this geometric proof activity, students compose 20 triangle congruency proofs. Students will decide if there is enough information in problems 1-6 to prove if any triangles are congruent. In problems 17 to 20, students use given...
Activity
Illustrative Mathematics

Reflections and Isosceles Triangles

For Teachers 9th - 11th Standards
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...
Lesson Plan
Houghton Mifflin Harcourt

Developing the Concept: Triangles and Quadrilaterals

For Teachers 5th - 7th Standards
Exact narrative and examples make this lesson on polygons easy to implement. Through it, your class will learn how to use a protractor and ruler to construct triangles and quadrilaterals according to your directions. Your class will be...
Worksheet
Curated OER

Countdown Challenge: Tangrams

For Students 7th - 8th
In this tangram worksheet, students find the area of each tangram shape. Afterwards, they name each piece and find the area of combined figures. This one-page worksheet contains approximately 25 problems.
Lesson Plan
Curated OER

The Centroid of a Triangle

For Teachers 9th - 10th
Students 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 area.
Lesson Plan
Curated OER

Symmetry and Geometric Shapes on Campus

For Teachers 6th - 8th
Build on your learners' previous knowledge of geometric shapes and symmetrical figures. Then set them out to take photos of geometric shapes on campus. They assess whether the photos contain symmetry or not. 
Lesson Plan
Futures Channel

Folding Circles

For Teachers 7th - 12th Standards
Students investigate properties of circles. In this geometry lesson plan, students differentiate between similarity and congruence as they observe polygons. They investigate properties of two and three dimensional shape.
Lesson Plan
Curated OER

The Pythagorean Theorem Lesson 2

For Teachers 8th - 12th
Learners discuss and review examples of the Pythagorean Theorem using a GSP, Geometer's Sketchpad, activity.
Unit Plan
Mathematics Vision Project

Circles: A Geometric Perspective

For Teachers 10th - 12th Standards
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...
Lesson Plan
EngageNY

Similarity and the Angle Bisector Theorem

For Teachers 9th - 10th Standards
Identifying and verifying reproducible patterns in mathematics is an essential skill. Mathematicians identify the relationship of sides when an angle is bisected in a triangle. Once the pupils determine the relationship, they prove it to...
Printables
Houghton Mifflin Harcourt

Unit 6 Math Vocabulary Cards (Grade 3)

For Teachers 3rd
A set of 49 math vocabulary cards ranges from angle to irregular polygon to parallel lines. Each sheet contains two cards: one with the word printed in bold text and the other with the definition.
Interactive
Scholastic

Study Jams! Similar Figures

For Students 5th - 8th Standards
Discover how triangles are congruent based on their sides, angles, and proportionality. Learners explore the ways to determine similarity at their own pace, and then they practice afterwards with an assessment.