How can learners use algebra to solve a geometry problem? Help learners create an equation that shows the relationship between the number of sides of a polygon and the sum of the interior angles. Students are asked to divide the...

Given a pair of parallel lines and a triangle in between, geometers prove that the sum of the interior angles is 180 degrees. This quick quest can be used as a pop quiz or exit ticket for your geometry class.

After learning that the sum of interior angles for triangles is 108 degrees, take it further to show that the sum of angles in any polygon is the same! Using hexagons, pupils practice finding the measure of the six congruent angles. Make...

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...

Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...

Prove the Angle Sum Theorem of a triangle using parallel line and transversal angle relationships. Pupils create a triangle from parallel lines and transversals. They find angle measures to show that the angles of a triangle must total...

This can be used as a critical thinking exercise in congruence or as a teaching tool when first introducing the concept. Four octagons are arranged in such a way that a square is formed in the middle. With this information, geometry...

Polygons — it's all about the angles. Groups work with dynamic geometry software to find the sum of the measures of the angles of various polygons. After finding the information for several polygons, the groups generate a formula that...

Young scholars draw triangles and explore the classification of each using the measures of interior angles and lengths of sides. They investigate the sum of the interior angles of various triangles and conjecture and prove the theorem:...

Students find the sum of the angles of a polygon and construct a polygon given the number of sides. In this polygon lesson plan, students draw large polygons on the floor of the room. They measure the length of each side and the interior...

Have fun calculating angles for different polygons. The class differentiate the relationship between the interior and exterior angles of polygons. They discuss linear pair as it related the polygons and their angles. This is done as they...

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...

High schoolers explore quadrilaterals in this geometry lesson. They will draw a quadrilateral, measure the angles, and find the sum of the measures of the interior angles using Cabri Jr. The interactive capabilities of Cabri Jr. allow...

Sixth graders discover the patterns of sums of polygon angles. In this math lesson, 6th graders study the properties of geometric shapes to solve problems as they participate in hands-on activities.

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...

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...

Learners identify the interior and exterior measures of polygons. In this geometry lesson, students identify the formula for interior angles of polygons. They differentiate between triangular and polygons angles.

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...

Students investigate the interior angles of a triangle. In this geometry instructional activity, students create the formula to calculate the angles inside a triangle. They observe the total sum of a triangles angle on the navigator.

Learners explore the measures of the angles of a triangle in this geometry lesson plan. They use Cabri Jr. to investigate the sum of the measures of the interior angles of a triangle, and examine the relationships between the interior...

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.

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...

Tenth graders explore the exterior and interior angles of triangles. They use a theorem in order to prove a theorem about all polygons. Students use the theorem and its applications to find the angles of different types of triangles.

Students discover the sum of the interior and exterior angles of several polygons. In this Geometers sketchpad lesson, students work in groups to find the stated measurements of triangles, quadrilaterals, pentagons and hexagons. Students...