CK-12 Foundation
Supplementary and Complementary Angle Pairs
Complement and supplement your knowledge of angles. Young mathematicians study supplementary and complementary angle pairs using an interactive. A set of challenge questions solidifies this understanding.
CK-12 Foundation
Angle Pairs: Angle Measurements
As one changes, so does the other. Scholars use an interactive to see how changes in the measure of one angle of a complementary or supplementary pair of angles affect the measure of the other angle. They answer a set of challenge...
CK-12 Foundation
Proofs: Angle Pairs and Segments—The Three Angle Problem
Finding the sum of the measures of three angles is easy, unless you have no clue what the measures are. Learners use an interactive diagram to see a geometric problem in a different way. A set of challenge questions takes them through...
Curated OER
Triangle's Interior Angles
Given a pair of parallel lines and a triangle in between, geometers prove that the sum of the interior angles is 180 degrees. This quick quest can be used as a pop quiz or exit ticket for your geometry class.
Alabama Learning Exchange
Coordinate Geometry
Where do the coordinates lead? As children brainstorm ways to find the location of different buildings, they learn about coordinate points and how to use them to locate areas on a grid or map. They practice using ordered pairs by playing...
Teachers' Domain
Introduction to Angle Measure
An all-encompassing package provides video clips that demonstrate real-world activities that have to do with angles. After watching the Cyberchase cartoons, learners discuss why a "v" shape is used to measure a turn. A pair of vital...
EngageNY
Inscribed Angle Theorem and Its Applications
Inscribed angles are central to the lesson. Young mathematicians build upon concepts learned in the previous lesson and formalize the Inscribed Angle Theorem relating inscribed and central angles. The lesson then guides learners to prove...
EngageNY
Congruence Criteria for Triangles—AAS and HL
How can you prove it? Guide classes through an exploration of two possible triangle congruence criteria: AAS and HL. Learners connect this criteria to those previous learned and also explore criteria that does not work. The instructional...
CK-12 Foundation
Supplementary Angles: Spiderweb Angles
The itsy, bitsy spider went up the virtual wall. An interactive allows users to change the angles in a spider web. They must attend to supplementary angles as they answer challenge questions throughout the interactive.
Royal Society of Chemistry
Shapes of Molecules—Geometry of Central Atom
How is a molecule's shape determined? Explore bond angles, lone pairs, and VSEPR theory through a logic-based activity. Chemists pull together information about the major molecular shapes, then use it to solve puzzles.
Curated OER
Angle Pairs: Vertical Angles
In this geometry worksheet, 10th graders define vertical angles as it relates to interesting lines. There are 24 problems about solving vertical angles.
Curated OER
Angle Relationships
Young scholars investigate geometric relationship using conjecture about linear pairs and vertical angles. For this geometry lesson, students apply their theorems and previous geometry knowledge to solve for and find angles of linear...
Curated OER
Geometry - Angles Overview
Learners address 14 questions that include naming all pairs of opposite and supplementary angles for sets of intersecting lines and then, finding the measure of the unknown angle. They determine the measure of the angle that is...
EngageNY
Solve for Unknown Angles—Angles in a Triangle
Assist your class with each angle of geometry as they use exterior angles to form linear pairs with adjacent interior angles. They cover multiple vocabulary terms and work practice problems, complete with justifications, before taking an...
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...
Curated OER
Properties of Polygons, Parallel Sides, and Right Angles
Have fun with shapes! Third graders read a set of instructions and circle the shape in the description. They work on recognizing parallel sides and right sides. Use this resource as homework after your geometry lesson.
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...
CK-12 Foundation
Linear Pairs
Pair up this resource with a lesson on linear pairs. Scholars solve for missing variables and values of angles in linear pairs. They use an interactive to help with this endeavor.
CK-12 Foundation
Vertical Angles
Examine vertical angles from a different angle. Moving one line in an intersecting pair of lines lets users see relationships between vertical angles. They finish by answering some machine-scored questions on the topic.
Curated OER
Semester 1 Review for Geometry final
In this geometry worksheet, 10th graders solve problems that are based on the topics covered in a first semester geometry class, including, linear equations and the equations of parallel and perpendicular lines, the logic of geometry,...
Curated OER
Angle Pairs
Students identify different angle pairs. In this geometry lesson plan, students identify the different angles of two parallel lines cut by a transversal. They identify the interior and exterior angles.
Geometry Accelerated
Accelerated Geometry Review Sheet
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
Curated OER
Quiz: Angles with Parallel Lines
Middle schoolers identify all pairs of angles formed from parallel lines and a transversal. They use the definitions of alternate interior, alternate exterior and corresponding angles to determine the value of given angles. This one-page...
EngageNY
Base Angles of Isosceles Triangles
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...