Curated OER
Angle Relationships
Over the course of 18 problems, learners identify angles as complementary, supplementary, vertical or adjacent. They name relationships in angles such as alternate interior, corresponding, and alternate exterior angles. They apply the...
Curated OER
Angle Relationships
Students investigate geometric relationship using conjecture about linear pairs and vertical angles. In this geometry lesson, students apply their theorems and previous geometry knowledge to solve for and find angles of linear pairs....
University of Utah
Geometry: Angles, Triangles, and Distance
The Pythagorean Theorem is a staple of middle school geometry. Scholars first investigate angle relationships, both in triangles and in parallel lines with a transversal, before proving and applying the Pythagorean Theorem.
EngageNY
Angles Associated with Parallel Lines
Explore angle relationships created by parallel lines and transversals. The 13th instructional activity of 18 prompts scholars use transparency paper to discover angle relationships related to transversals. Learners find out that these...
Curated OER
Angle Relationships
Tenth graders explore the angle relationships that exist when two lines intersect. In this geometry lesson, 10th graders estimate the measure of given angles and use their graphing calculator tools. Students use this knowledge to find...
EngageNY
The Angle Measure of an Arc
How do you find the measure of an arc? Learners first review relationships between central and inscribed angles. They then investigate the relationship between these angles and their intercepted arcs to extend the Inscribed Angle Theorem...
EngageNY
Solve for Unknown Angles—Angles and Lines at a Point
How do you solve for an unknown angle? In this sixth installment of a 36-part series, young mathematicians use concepts learned in middle school geometry to set up and solve linear equations to find angle measures.
Curated OER
Angles, Lines, and Transversals
Geometers identify and determine angle pair relationships when two parallel lines are intersected by a transversal. They review the concepts of angles by watching streaming video clips online, read definitions of lines and angles from...
Virginia Department of Education
Lines and Angles
Explore angle relationships associated with transversals. Pupils construct parallel lines with a transversal and find the measures of the angles formed. They figure out how the different angles are related before constructing...
Curated OER
Supplementary, Complementary, and Vertical Angles
By using circles that they cut out and label themselves, learners literally "get a grip" on the angles they identify: supplementary, complementary, and vertical. They solve missing measurements based on properties of supplementary,...
Curated OER
Know Your Angles
Explore types of angles and the characteristics of each. After observing a PowerPoint Presentation, learners tour the school facilities and use a digital camera to capture prescribed angles. Using the digital pictures and written...
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...
Texas Instruments
Identifying a Triangle by its Sides and Angles
Identify triangles by their angle measures and side lengths by looking at and measuring angle measures and side lengths. Use Cabri Jr. to construct various triangles, then manipulate the construction to create the 6 types of triangles,...
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.
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...
CCSS Math Activities
Smarter Balanced Sample Items: 7th Grade Math – Target F
Sometimes it's how you ask the question that counts. The sixth installment of nine from the Smarter Balanced Claim 1 Slideshow series presents a set of 13 questions to assess understanding of angle relationships as well as area and...
Willow Tree
Angles Formed by Transversals of Coplanar Lines
Create a strong understanding of the relationships formed when parallel lines intersect a transversal. Discuss each type of angle pair and their relationship to each other.
Virginia Department of Education
Angles, Arcs, and Segments in Circles
Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...
EngageNY
Secant Angle Theorem, Exterior Case
It doesn't matter whether secant lines intersect inside or outside the circle, right? Scholars extend concepts from the previous instructional activity to investigate angles created by secant lines that intersect at a point exterior to...
EngageNY
Unknown Angle Problems with Inscribed Angles in Circles
We know theorems about circles—now what? Class members prove a theorem, with half the class taking the case where a point is inside the circle and half the class taking the case where a point is outside the circle. The lesson then...
Alabama Learning Exchange
Unit Circle: Special Angles—Just Know One
It's all about the patterns! Young scholars learn that the unit circle repeats itself in all four quadrants. Using these patterns, they evaluate the sine, cosine, and tangent of special angles.
Mathematics Vision Project
Similarity and Right Triangle Trigonometry
Starting with similar triangles and dilation factors, this unit quickly and thoroughly progresses into the world of right triangle features and trigonometric relationships. Presented in easy-to-attack modules with copious application...
West Contra Costa Unified School District
Arcs and Angles
Noah didn't construct this kind of arc. High school scholars first explore how angles can be formed in circles. They then learn relationships between angles and arcs by conducting an exploratory activity where they position and draw arcs...
EngageNY
Sine and Cosine of Complementary Angles and Special Angles
Building trigonometric basics here will last a mathematical lifetime. Learners expand on the previous lesson in a 36-part series by examining relationships between the sine and cosine of complementary angles. They also review the ratios...