After reviewing characteristics of seven types of triangles, young geometers discover how to find the missing angle of a triangle. Then, they practice identifying triangles, find missing angles, and find missing side lengths of...

With so many different types of triangles, it can be a challenge for young mathematicians to keep them all straight. Luckily this set of printable triangles is here to engage children in comparing and sorting triangles by their...

The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...

Jam on with this multi-faceted activity teaching triangle classification. Start with a learner-paced lesson describing the different qualities of triangles and follow with a fun karaoke session. Also provided are two types...

Take your class on a field trip to Fractalland where they'll learn all about number and shape patterns. Based on Disney's movie Alice in Wonderland, this resource takes young mathematicians on an adventure as they explore patterns in...

Building on young mathematicians' prior knowledge of three-sided shapes, this lesson plan series explores the defining characteristics of different types of triangles. Starting with a shared reading of the children's book The Greedy...

Using the Pythagorean Theorem to solve for missing angles, young scholars evaluate right triangles and their properties.

Learn to use the Pythagorean Theorem with non-right triangles. Pupils use the interactive to discover the relationship between the lengths of sides for acute and obtuse triangles. They compare the squares of the sides of the triangles to...

Explore vocabulary and notation related to triangles and congruence. The fifth lesson in the 29-part series helps pupils build their knowledge of triangle relationships. Individuals identify corresponding parts of identical triangles and...

Create concrete examples of triangle congruence for your classes. The eighth installment of the 29-part module sets the stage for studying triangle congruence. Given a set of criteria, math scholars use constructions to build a specific...

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...

Examine an assortment of triangle congruence criteria in a single lesson. Building on the four previous lessons of the series, the 13th installment provides a mixture of the different triangle congruence criteria for pupils to identify....

Building on the previous lesson in the 29-part series, the ninth lesson asks individuals to construct a triangle given specific criteria. First, they are given three specific side lengths, followed by two sides and the included angle....

Given a diagram of connected or overlapping triangles, individuals must find congruent parts using various properties. Pictures include reflexive sides and vertical angles amongst the marked congruent parts.

Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...

Young mathematicians explore the world of three-sided shapes in this lesson on the different types of triangles. Starting with a general introduction to classification using Venn diagrams, children learn how to categorize triangles...

Learners study acute triangles. They measure angles using a protractor, then classify the triangles as either right, obtuse, or acute. Everyone creates a design for a Navajo rug using only acute triangles.

Fourth graders explore triangles. In this math lesson, 4th graders discuss the different types of triangles. Students create triangles using wiki sticks. Students complete an online matching game.

Sixth graders investigate triangles and the inequality theorem. They will collaborate in groups to determine the length of a longest side of a triangle. Then relate the size of the triangle to its angles using protractors, yard sticks,...

Students estimate and measure triangles. In this geometry lesson, students identify the relationship between three sides and a triangle. They use the inequality theorem to decide if a triangle will be formed or not.

Geometers prove that triangle PQR is congruent to triangle ABC by describing any combination of rotations, reflections, and translations that would prove it so. There is only this single task on the handout, but a detailed explanation of...

Youngsters identify and draw polygons including squares, rectangles, and right triangles. In this polygons lesson plan, everyone draws these shapes that have right angles in their math journals.

Solve that triangle! Your class examines angles and side measurements on 20 right triangles to determine the missing measurements. For some, they are given two sides while for others, they are given an angle and a side.

Under which conditions can a triangle be classified as isosceles? High schoolers practice identifying isosceles triangles and special line segments, including angle bisectors, medians of triangles, and perpendicular bisectors of sides of...