Curated OER
Properties of Angles, Lines, and Triangles
In this properties of angles, lines and triangles worksheet, 10th graders solve and complete 28 different problems that include determining the measurement of various figures shown. First, they use the geometric properties and theorems...
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...
Willow Tree
Angle Sum Property of Triangles
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 instructional activity.
Mathematics Assessment Project
Applying Angle Theorems
Polygon ... an empty bird cage? After finding the angles of a polygon, young mathematicians use the provided methods to solve the problem in multiple ways.
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
Similarity and the Angle Bisector Theorem
Identifying and verifying reproducible patterns in mathematics is an essential skill. Mathematicians identify the relationship of sides when an angle is bisected in a triangle. Once the pupils determine the relationship, they prove it to...
Mathed Up!
Angles: Parallel Lines
Viewers are presented with seven problems with parallel lines and angle relationships and must use the given information to find the measures of specific angles. To finish, they explain their process in finding the measures in the problems.
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 instructional activity, 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, high schoolers 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 lesson provides an...
Curated OER
Triangle Classificaition with Geometer's Sketchpad.
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.
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...
Charleston School District
Parallel Lines Cut by a Transversal
Pupils study angle measurements between different types of angles associated with parallel lines and transversals. The independent practice asks pupils to identify the types of angles in a diagram and to determine the measure of angles.
Curated OER
Midsegments of a Triangle
Students analyze midsegments of triangles in this lesson plan. They use Cabri Jr. software to observe the relationships between interior angles and midsegments of triangles. Specific instructions for creating this lesson plan in Cabri...
Primary Resources
Different Types of Triangles
Are there different types of triangles? Yes there are, and this presentation describes each by its properties or characteristics. Right, equilateral, isosceles, and scalene are all shown and defined. The presentation isn't particularly...
Curated OER
Interior and Exterior Angles of Polygons
In this angles of polygons learning exercise, 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...
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
Ratios in Right Triangles
Learners calculate the sides of right triangles in this trigonometric ratios instructional activity. They use Cabri Jr. software and TI-83 or TI-84 calculators to find the side lengths and their ratios to each other for various...
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 lesson.
Curated OER
Measuring Angles in Triangles
For this measuring angles in triangles worksheet, 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...
Houghton Mifflin Harcourt
Unit 5 Math Vocabulary Cards (Grade 6)
Acute angle, line of symmetry, and vertex are a few terms you'll find in a set of 90 flashcards designed to reinforce math vocabulary. Included in the set are two types of cards; a word card printed in bold font, and a definition card...
EngageNY
Angle Sum of a Triangle
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...