Virginia Department of Education
Angles in Polygons
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...
Curated OER
Triangle Fundamentals
In this geometry worksheet, students observe a triangle marked with three angles and are given two measures to find the missing third measure. A second diagram is given with six angles. There are 20 questions.
Curated OER
Measuring Angles in Triangles
In this measuring angles in triangles activity, 10th graders solve 12 different measurement problems with angles within triangles. First, they find the value of x in each triangle given the angle measurements. Then, students find the...
Curated OER
Angles of a Triangle
Learners explore the measures of the angles of a triangle in this geometry lesson. 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 and...
Curated OER
Shapes and Designs
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...
Curated OER
Geometric Figure Quiz
In this geometric figure worksheet, students answer 10 multiple choice questions about geometric figures. Students find missing angles, interior angles, properties of polygons, etc.
Curated OER
Polygons Homework
In this polygons worksheet, students identify polygons that contain given parameters. They write definitions of polygons. Students find the measurement of exterior and interior angles of regular polygons. This two-page worksheet...
Curated OER
Measuring Angles in a Triangle
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 instructional...
Curated OER
Angle Bisectors
In this angle bisector worksheet, 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...
Utah Education Network (UEN)
Geometric Figures and Scale Drawings
Scale up your lessons on geometry and ask learners to investigate conditions on triangles, scale drawings, the area and circumference of circles, and angle relationships. The resource includes activities and a homework assignment.
Curated OER
Triangles
In this triangles worksheet, 10th graders solve 12 different problems that include various angles of triangles. First, they determine the measure of an exterior angle. Then, students determine the measure of any of the base angles of an...
Curated OER
Interior and Exterior Angles of Polygons
In this angles of polygons worksheet, 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 first half of...
Improving Measurement and Geometry in Elementary Schools
The Sum of the Interior Angles of a Polygon
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...
Curated OER
Geometric Properties
Students find triangular angles using the angle theorem. For this geometry lesson, students describe labeled triangles, use the pythagorean theorem, and rewrite information about triangles in standard form.
Inside Mathematics
Circles in Triangles
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
GeoGebra
Conjectures and Proof
Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...
Radford University
How Much is in There? A Polygon Investigation
Try to find the triangles in various polygons. An investigation has learners develop a formula for the sum of the measures of the interior angles of a polygon. They use manipulatives to partition each polygon into triangles, then...
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
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 practice...
EngageNY
Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams
First angle measures, now segment lengths. High schoolers first measure segments formed by secants that intersect interior to a circle, secants that intersect exterior to a circle, and a secant and a tangent that intersect exterior to a...
Curated OER
Polygon Sum Conjecture
In this geometry worksheet, 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.
Curated OER
Polygons
Young scholars 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...
Curated OER
Interior/Exterior Polygon Angles and Tessellations
Students discover the sum of the interior and exterior angles of several polygons. In this Geometers sketchpad instructional activity, students work in groups to find the stated measurements of triangles, quadrilaterals, pentagons and...
Curated OER
Patterns in the Sums of Polygon Angles
Sixth graders are introduced to how to calculate the interior angles of polygons. Using a worksheet from a previous lesson, they use those answers to determine the sum of the angles of the pattern blocks. To end the lesson, they tear...
Willow Tree
Common Geometric Figures
Geometry could be called the study of figures. An overview of the figures found in a typical geometry course contains a study of different triangles, quadrilaterals, and regular polygons.