+
Lesson Plan
Curated OER

Triangles and Quadrilaterals

For Teachers 2nd
Second graders explore triangles and quadrilaterals. They rotate to various centers in the room to identify and examine triangles and quadrilaterals. After presenting a picture to the class, 2nd graders locate right angles, triangles...
+
Worksheet
Curated OER

Congruence of Triangles

For Students 10th
In this congruence of triangles worksheet, 10th graders solve 10 different problems that include determining the congruence of various triangles. First, they determine the length of two sides of a congruent triangle. Then, students...
+
Lesson Plan
Curated OER

Let's Explore the World of Triangles and Quadrilaterals!

For Teachers 2nd
Second graders explore the features of triangles and quadrilaterals. In this lesson on triangles and quadrilaterals, 2nd graders rotate with their group to five different activities all exploring a different aspect of geometry.
+
Worksheet
Curated OER

Triangles

For Students 6th - 10th
In this triangles worksheet, students solve for the missing angles and missing sides on the triangles given. Students complete 12 problems total.
+
Lesson Plan
Curated OER

Review Geometry - Week 8 (Triangles)

For Teachers 11th - 12th
For this triangle worksheet, pupils use similar figures to find the length of one side of two similar triangles. They find the area of a triangle inscribed in a rectangle. This two-page worksheet contains eight problems.
+
Worksheet
Curated OER

Triangles

For Students 4th - 5th
In this triangle instructional activity, students solve a set of 6 riddles involving the length of triangles and identifying types of triangles.
+
Lesson Plan
Curated OER

Angles And Triangles

For Teachers 7th
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....
+
Worksheet
Curated OER

Triangle Exercises

For Students 6th - 8th
In this math worksheet, students determine the name for each triangle according to its classification. Then they create a truss construction model.
+
Worksheet
Curated OER

Triangles

For Students 10th
In this triangles worksheet, 10th graders solve 10 different problems that include determining the measurement of various angles. First, they determine the area of a triangle illustrated on the sheet. Then, students use the picture to...
+
Worksheet
Curated OER

Triangles Word Search

For Students 5th - 6th
In this word search worksheet, learners locate 7 types of triangles. Triangles include isosceles, acute, equilateral, right, and obtuse.
+
Worksheet
Curated OER

Proofs

For Students 8th - 11th
In this geometric proof worksheet, 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...
+
Lesson Plan
Curated OER

What's in a Shape?

For Teachers 3rd - 5th
Pupils explore characteristics of shapes by making and using tangram sets. They discover how the tangram pieces are related to one another, and determine how many different combinations of the triangles, squares, and parallelograms in...
+
Lesson Plan
Curated OER

2-D polygons

For Teachers 3rd - 6th
A hands-on activity uses the Zome modeling system, and helps young geometers either learn or review their knowledge of polygons. Students build as many different 2-dimensional polygons as possible: triangle, square, rectangle, pentagon,...
+
Worksheet
Curated OER

Classifying Triangles

For Students 10th
In this classifying triangles worksheet, 10th graders solve 12 different problems that include classifying various types of triangles. They classify and then identify each of the given triangles as isosceles, scalene, or equilateral....
+
Worksheet
Curated OER

Geometry and Triangles

For Students 11th - Higher Ed
In this geometry triangles activity, students first determine how many degrees are found in one half and in three-fifths a revolution. Then they find the supplement of the two angles given and the radius of a circle. Students also...
+
Worksheet
Curated OER

Finding the Angle Measurements in Isosceles Triangles

For Students 9th
In this angles worksheet, 9th graders find the angle measurements in four isosceles triangles.  Two of these triangles are drawn inside a circle, where two of the sides of the triangles are formed by radii.
+
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...
+
Lesson Plan
Curated OER

Review of Triangles

For Teachers 8th - 10th
Students investigate the Pythagorean Theorem. In this geometry instructional activity, students define angles and sides of right triangles. They calculate the area and surface area using formulas derived by the Pythagorean Theorem.
+
Assessment
Concord Consortium

Three Rubber Bands

For Students 7th - 12th Standards
Stretch your mind about triangles. Given a triangle, scholars consider a smaller triangle formed when they stretch three rubber bands from each vertex to the opposite side. They determine the ratios of the areas and perimeters of the...
+
Worksheet
Curated OER

Perimetr of Isosceles Triangle

For Students 9th - 10th
In this geometry worksheet, students calculate the perimeter of isosceles triangles given the sides of the triangles. There are 6 questions with an answer key.
+
Lesson Plan
Curated OER

Twenty-Five Measures of the Angles of a Triangle Problems

For Teachers 9th - 10th
For this triangle worksheet, students calculate the measures of the angles or the sums of the measures of the angles in twenty-five triangle problems and hands-on activities.  The solutions are provided.
+
Lesson Plan
Curated OER

Scalene Triangles

For Teachers 5th
Fifth graders identify and classify scalene, equilateral, and isosceles triangles. In this triangle lesson, 5th graders define the different attributes of 3 types of triangles and sort them by descriptions and comparisons. Students...
+
Lesson Plan
Curated OER

Isosceles Triangle Investigation

For Teachers 9th - 12th
Students solve problems with isosceles triangles. In this geometry instructional activity, students identify and use the properties of triangles to solve their problems. They find the median, altitude, and angles to the triangles.