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...
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
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 lesson...
Flipped Math
Measuring Angles
An informative presentation shows pupils how to name and measure angles. Scholars revisit the different types of angles and their definitions and use their knowledge of what an angle bisector is to solve algebraic problems. At the end,...
Willow Tree
Interior Angles, Exterior Angles, and Diagonals of Polygons
How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate the number of...
Willow Tree
Angle Measurement
What do you create when you rotate a ray? An angle! Teach all the angle basics including naming, measuring, supplements, and complements.
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 lesson.
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...
Mathematics Vision Project
Geometric Figures
Logical thinking is at the forefront of this jam-packed lesson, with young mathematicians not only investigating geometric concepts but also how they "know what they know". Through each activity and worksheet, learners wrestle with...
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...
Corbett Maths
Constructing SAS Triangles
Two sides and an angle ... a triangle it makes. Given the measure to two sides and the angle between them, the narrator of a short video shows how to draw a triangle with a ruler and protractor. Pupils use handouts to practice the newly...
Mathed Up!
Bearings
Keep the math straight and true. Using information learned about angle relationships, pupils determine drawn bearings, or draw a line with a given bearing. The accompanying video provides the definition of a bearing and its three...
Corbett Maths
Constructing ASA Triangles
The narrator of a short video explains the steps in constructing a triangle given the measure of two angles and the length of the side between the angles. The resource provides opportunities for pupils to practice the skill with two...
Mathed Up!
Loci and Constructions
A General Certificate of Secondary Education math review has class members make basic constructions. Using a protractor and a ruler along with a compass, pupils develop drawings of triangles with given measurements. Scholars use their...
Flipped Math
Chords and Arcs
Congruence breeds congruence. Pupils learn three more circle theorems dealing with congruent chords and arcs. Learners use the theorems to find the measures of chords and arcs in circles by applying previously learned concepts in the...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
EngageNY
Writing and Solving Linear Equations
Incorporate geometry into the solving linear equations lesson. Pupils use their knowledge of geometry to write linear equations which reinforces geometry measurement concepts while at the same time providing a familiar context for...
Curated OER
Transformations in the Coordinate Plane
Your learners connect the new concepts of transformations in the coordinate plane to their previous knowledge using the solid vocabulary development in this unit. Like a foreign language, mathematics has its own set of vocabulary terms...
Virginia Department of Education
Constructions
Pupils learn the steps for basic constructions using a straightedge, a compass, and a pencil. Pairs develop the skills to copy a segment and an angle, bisect a segment and an angle, and construct parallel and perpendicular lines.
PBS
Accessible Shapes
All the 2-D and 3-D measurement work you need is in one location. Divided into three sections, the geometry lesson plans consist of visualization of three dimensions, classifying geometric figures, and finding surface area and volume....
EngageNY
Putting the Law of Cosines and the Law of Sines to Use
Use the Law of Cosines and the Law of Sines to solve problems using the sums of vectors. Pupils work on several different types of real-world problems that can be modeled using triangles with three known measurements. In the process,...
Cornell University
Constructing and Visualizing Topographic Profiles
Militaries throughout history have used topography information to plan strategies, yet many pupils today don't understand it. Scholars use Legos and a contour gauge to understand how to construct and visualize topographic profiles. This...
EngageNY
Informal Proofs of Properties of Dilations
Challenge the class to prove that the dilation properties always hold. The lesson develops an informal proof of the properties of dilations through a discussion. Two of the proofs are verified with each class member performing the...
Willow Tree
Circle Graphs
Pie isn't just for eating! Scholars learn to create pie charts and circle graphs to represent data. Given raw data, learners determine the percent of the whole for each category and then figure out the degree of the circle that percent...