All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the lesson.

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,...

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

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

One of the basic properties of inscribed angles gets a triangle proof treatment in a short but detailed exercise. Leading directions take the learner through identifying characteristics of a circle and how they relate to angles and...

Lead the class in a Greek history lesson with a geometric twist. Pupils relate a short video about geometric properties to modern-day methods of solving for unknown angles. They discuss parallel line theorems and complete...

Something for young mathematicians to remember: the sum of any two sides must be greater than the third. Class members investigates the Triangle Inequality Theorem to find the relationship between the sides of a triangle. At the...

Learners estimate and measure triangles. In this geometry instructional activity, 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.

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

Can any three side lengths create a triangle? Your classes tackle this question and more in the 11th lesson of the 29-part module. Through modeling with patty paper, individuals discover the relationship between the lengths of the sides...

How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate...

Fifth graders investigate possible solutions to a word problem. They explore properties of polygons and right angles. Students demonstrate proper angle measurement. Students discover patterns.

Angles and triangles: they're all connected. Uncover the connections between angles in triangles. Scholars learn how to find both exterior and interior angle measures in triangles. The lesson emphasizes the vocabulary related to these...

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

Assist your class with each angle of geometry as they use exterior angles to form linear pairs with adjacent interior angles. They cover multiple vocabulary terms and work practice problems, complete with justifications, before...

High schoolers investigate the sum of the measures of the angles of a triangle. They draw a triangle and measure the interior angles. Using Cabri Jr., learners find the sum of the measures of the interior angles. The lesson provides an...

Teach your class how to solve problems using the triangle sum theorem. For this geometry lesson, students identify the missing angles in a triangle using the sum theorem. They graph triangles on the TI and moves the sides around to...

What does it take to show two triangles are similar? The 11th segment in a series of 16 introduces the AA Criterion for Similarity. A discussion provides an informal proof of the theorem. Exercises and problems require scholars to apply...

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.

Students add up the different angles using the angle addition postulate. In this geometry lesson, students differentiate between interior and exterior angles. They calculate the different angles for triangles and use proof to show their...

Pupils calculate angle measure for triangles and complementary/supplementary angles. After a lecture/demo, students utilize a worksheet imbedded in this plan to gain practice.

Junior geometers discover that polygons can be decomposed into triangles and that the number of triangles can be determined by a rule. Note that the Geometer’s Sketchpad® software is required to carry out all components of this...

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...

Guide your geometers through the process of constructing polygons. They learn how to draw triangles, squares, parallelograms, rectangles, rhombuses, and trapezoids with specified angles using a protractor and a ruler. The lesson plan...