What can symmetry tell us about triangles? After looking at four examples, learners will come to realize that lines of symmetry are different for equilateral, isosceles, and scalene triangles. Use this guided practice activity as an...

Identify triangles by their angle measures and side lengths by looking at and measuring angle measures and side lengths. Use Cabri Jr. to construct various triangles, then manipulate the construction to create the 6 types of triangles,...

Students draw a chart (included in the lesson) to use with their investigation. They review terminology of triangles and receive toothpicks to use in the lesson. Beginning with three toothpicks, students form a triangle. They complete...

How many different types of triangles can your class name? A discovery lesson guides learners through an exploration of the different triangle types and the relationships between their angles and sides. Using coordinate geometry,...

Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...

How do you know if a pair of triangles are congruent? Use the instructional activity to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through...

Learners explore the difference between a construction and a drawing. They focus on various ways to construct different types of triangles. The lesson is an application of Cabri Jr. and reinforces the difference between a constructions...

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.

You're safe, when calculating the odds of stealing second base! Learners compare the rate of a runner to the distance the ball travels, in a lesson that explores right triangles and measurement. Full of discussion questions and fun...

Students find triangular angles using the angle theorem. In this geometry instructional activity, students describe labeled triangles, use the pythagorean theorem, and rewrite information about triangles in standard form.

Students use the inequality theorem to solve triangles and their properties. In this geometry lesson, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...

Given the lines of symmetry in an equilateral triangle, your learners find where the pre-image vertices are mapped onto the new image. They explore the properties of equilateral triangles, the impact of reflections, and the...

Why was Pythagoras so obsessed with squares? The assessment task posits the question of whether the geometric interpretation of the Pythagorean Theorem holds for figures other than squares. Scholars first consider the case of semicircles...

Students identify the properties of an isosceles triangle. For this geometry lesson, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.

Students identify different types of special right triangles. In this geometry lesson, students differentiate between right triangles and isosceles triangles. they construct the triangles using geometry software and make conjectures...

Fourth graders explore obtuse triangles. In this geometry lesson, 4th graders make obtuse triangles with paper and scissors. They determine how to find the center of their triangle.

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.

Young scholars investigate the Pythagorean Theorem. In this geometry lesson, students define angles and sides of right triangles. They calculate the area and surface area using formulas derived by the Pythagorean Theorem.

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...

Students solve problems with isosceles triangles. In this geometry lesson, students identify and use the properties of triangles to solve their problems. They find the median, altitude, and angles to the triangles.

Students classify different types of triangles. For this geometry lesson, students identify and use properties of triangles. They differentiate between isosceles and equilateral triangles.

Divide and conquer the geometry problem. Young scholars consider how to subdivide triangles into smaller ones that have equal areas. They must apply their knowledge of medians to help accomplish the task.

Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts...

What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...