Lesson Plan
Curated OER

Interior Angles of Regular Polygons

For Teachers 9th - 12th Standards
High schoolers investigate the interior angles of a triangle. In this geometry lesson, students create the formula to calculate the angles inside a triangle. They observe the total sum of a triangles angle on the navigator.
Lesson Plan
Willow Tree

Angle Sum Property of Triangles

For Students 8th - 11th Standards
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.
Worksheet
Curated OER

Shapes and Designs

For Students 10th
In this shapes and designs worksheet, 10th graders solve and complete 6 different types of problems. First, they fill in the first two columns of the table show with their shapes. Then, students measure the interior angles of each...
Worksheet
Curated OER

Properties and Attributes of Polygons

For Students 10th
In this geometry instructional activity, 10th graders determine if a polygon is convex or concave and apply the polygon Angle sum theorem and the polygon exterior angle sum theorem to determine the measures of interior and exterior...
Lesson Plan
Curated OER

Interior/Exterior Polygon Angles and Tessellations

For Teachers 9th - 11th
Students discover the sum of the interior and exterior angles of several polygons. For this Geometers sketchpad lesson, students work in groups to find the stated measurements of triangles, quadrilaterals, pentagons and hexagons....
Worksheet
Curated OER

Angle Bisectors

For Students 10th
In this angle bisector activity, 10th graders solve and complete 23 various types of geometry problems. First, they find the angles listed in the figure shown. Then, students determine the sum of the interior angles of a polygon. They...
Lesson Plan
Curated OER

Exploring Characteristics of Triangles

For Teachers 9th - 11th
Students 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: The...
Worksheet
Curated OER

Geometric Concepts and Polygons

For Students 9th - 11th
In this geometry worksheet, students identify the altitude, perpendicular bisector, median, angle bisector and the area of different polygons. There are 33 problems.
Lesson Plan
Curated OER

Polygons

For Teachers 5th - 7th
Students investigate the concepts related to the study of polygons. They specifically look at how angles is related. The lesson includes specific examples and dialogue to be used by the teacher during direct instruction and independent...
Handout
El Paso Community College

Geometry Definitions

For Students 7th - 9th Standards
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet. 
Worksheet
Curated OER

Interior and Exterior Angles of Polygons

For Students 10th
In this angles of polygons instructional activity, 10th graders solve and complete 18 different problems that include determining various interior and exterior angles. First, they determine the measure of various angles described in the...
Lesson Plan
Curated OER

Around The Stop Sign

For Teachers 6th - 12th
Students analyze a drawing of a regular octagon inscribed in a circle to determine angle measures, using knowledge of properties of regular polygons and the sums of angles in various polygons to help solve the problem. They use...
Lesson Plan
Curated OER

Polygons: Angles vs. Sides

For Teachers K - 4th
Students analyze the relationship between the number of sides of a polygon and the sum of its angles. Pattern blocks are utilized to trace the outside of the shapes. They make their own outline of a four-sided polygon from the replica of...
Lesson Plan
Curated OER

Tile Patterns I: Octagons and Squares

For Teachers 7th - 9th Standards
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...
Worksheet
Curated OER

Sums of Angles in Polygons

For Students 5th - 6th
In this angles in polygons worksheet, students determine the sum of internal angles and calculate x. A reference web site is given for additional activities.
Lesson Plan
Improving Measurement and Geometry in Elementary Schools

The Sum of the Interior Angles of a Polygon

For Teachers 4th - 5th Standards
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...
Worksheet
Curated OER

Tessellations Multiple Choice

For Students 7th - 9th
In this tessellations worksheet, students answer questions about the characteristics of tessellations.  They identify polygons that will and will not tessellate.  Students determine the sum of angles in a polygon...
Lesson Plan
Curated OER

Patterns in the Sums of Polygon Angles

For Teachers 6th
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.
Worksheet
Curated OER

Polygons

For Students 10th
In this polygons worksheet, 10th graders solve 10 different problems that include various types of polygons. First, they determine the number of sides that a polygon has if the exterior angle is a certain degree. Then, students determine...
Organizer
Curated OER

Triangle Angle-Sum Theorem

For Students 5th - 8th
In this polygons worksheet, students fill out a graphic organizer about the name of the polygon, the number of sides, the angle sums, and more. Students complete this for 5 polygons.
Lesson Plan
Curated OER

Lesson Exchange: Polygons (Middle, Mathematics)

For Teachers 6th - 7th
Students discover the relationship between the sides of a polygon and the number of diagonals that can be drawn from one vertex, the number of triangles that those diagonals form, and the sum of the interior angles of that polygon.
Worksheet
Curated OER

Area of Quadrilaterals

For Students 10th
For this area of quadrilaterals worksheet, 10th graders solve and complete 5 various types of problems. First, they solve each of the triangles shown and find the area of each triangle. Then, students prove that the sum of the squares of...
Interactive
Curated OER

Interior Angles of Polygons

For Students 9th - 12th
In this online math worksheet, students determine the interior angles of polygons given their exterior measurements. This excellent resource allows the students to check their answers, and to get "hints" should they run into...
Worksheet
Curated OER

Polygon Sum Conjecture

For Students 10th
In this geometry instructional activity, 10th graders identify the missing angles using the polygons sum conjecture. They measure exterior and interior angles using their angle theorems. There are 63 problems.