Curated OER
Circles and Angles
Students identify tangents, chords and secants. In this geometry lesson, students graph circles and identify angles created by secant lines, tangent lines and chords.
Curated OER
Angles, Lines and Transversals
Students identify and determine angle pair relationships. In this geometry lesson, students identify different angles of parallel lines that are cut by transversals. They identify interior and exterior angles after watching a video.
Alabama Learning Exchange
"I Saw the Sine"
Discover trigonometric ratios that complement each other. Using two videos, the lesson introduces the trigonometric ratios. The class discovers the relationship between the sine and cosine of complementary angles.
West Contra Costa Unified School District
Parallel Lines Cut by a Transversal
Parallel lines seem so right for each other. It's too bad they'll never, ever meet. Learners use tracing paper to discover relationships among angles formed by two parallel lines cut by a transversal. They apply this information to find...
Willow Tree
Ratios and Proportions with Congruent and Similar Polygons
Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...
Curated OER
Exploring Angle/Pair Relationships
Students find missing angles and sides of triangles. In this geometry lesson, students create intersecting lines to measure angles. They use Cabri Software to create virtual angles.
Curated OER
Determining Angle Measure with Parallel Lines
High schoolers observe and solve examples of corresponding angle postulates, alternate interior angle theorems, and exterior and consecutive angles. They complete the Determining Angle Measure With Parallel Lines worksheet.
Beacon Learning Center
Angles and Algebra
Students calculate angle measure for triangles and complementary/supplementary angles. After a lecture/demo, students utilize a worksheet imbedded in this plan to gain practice.
Curated OER
Rays and Angles
Students view examples of a ray, opposite rays, collinear rays, angles, and straight angles. They discuss and demonstrate how to use a protractor and complete worksheet problems on rays and angles.
Curated OER
Measuring Angles
In this measuring angles learning exercise, 10th graders solve and complete 8 various types of problems. First, they use a protractor to find the measure of each angle shown. Then, students find the missing angle measures. They also...
Curated OER
Measurement of a Central Angle
Students calculate the measurement of a central angle. In this geometry lesson, students identify properties of circles. They use Cabri software to create and analyze graphs.
Curated OER
How Do You Pay a Complement to an Angle?
Students observe and solve examples of the complementary angle theorem. They complete the How Do You Pay a Complement to an Angle worksheet, and write a response in their math journal.
Curated OER
Inscribed Angles
Students calculate the inscribed angle of a triangle. In this geometry instructional activity, students identify the angle created by intersection of a triangle and a circle. They see the relationship between the arc and the angle.
Curated OER
Perimeter
Students study about perimeter and the units used to measure perimeter using a variety of materials including their hands, feet, rulers, and computer applets. They understand such attributes as length, area, weight, volume, and size of...
Curated OER
Geometry: Lesson 8
Eighth graders engage in a lesson that is concerned with the finding of angles that are found in different two dimensional figures. They compare and contrast exterior and interior angles while also determining the unknown measures of...
Curated OER
Sextant Solutions
Students explore ways a sextant can be a reliable tool that is still being used by today's navigators and how computers can help assure accuracy when measuring angles. This activity will show how computers can be used to understand...
Flipped Math
Properties of Parallel Lines
Work within a parallel universe. Scholars learn about the relationships of angles when two parallel lines are intersected by a transversal. They see how to find the measurements of all eight angles by knowing the measure of one angle....
EngageNY
Prove the Pythagorean Theorem Using Similarity
Amaze your classes with the ability to find side lengths of triangles immediately — they'll all want to know your trick! Learners use the Pythagorean Theorem and special right triangle relationships to find missing side lengths.
Curated OER
Angles and Parallel Lines
In this angles and parallel lines activity, 10th graders solve 27 different variations of angle types and parallel lines. They name a linear pair, a pair of vertical angles, a pair of complementary angles, and a pair of supplementary...
Hotchalk
Triangle Sum Theorem
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...
EngageNY
End-of-Module Assessment Task: Grade 7 Mathematics Module 6
Determine the level of understanding within your classes using a summative assessment. As the final lesson in a 29-part module, the goal is to assess the topics addressed during the unit. Concepts range from linear angle relationships,...
Curated OER
Linear Pair Theorem
In this linear pair theorem worksheet, learners determine the measure of 6 linear pairs given the measure of one of the pairs.
Curated OER
Positive and Negative Angles and Arcs
To better understand that the intersection point of two lines lies inside a circle, learners use their keen measurement skills. They discuss arcs, rays, tangent lines, and reflex angles. Then, they put their skills to work as they...
Curated OER
Investigating Area Relationships
Learners investigate the area of various figures. They construct triangles and quadrilaterals using Cabri Jr. and discuss the relationships between different angles, side lengths, and figures.