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...
CK-12 Foundation
Angles: The Angle of Discovery
Practice important angle vocabulary using an interactive lesson. As learners manipulate vertical angles, they watch the supplementary and congruent angles adjust. Questions pertaining to vocabulary and measurements follow their exploration.
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history lesson with a geometric twist. Pupils relate a short video about geometric properties to modern-day methods of solving for unknown angles. They discuss parallel line theorems and complete...
Illustrative Mathematics
Find the Missing Angle
This one activity requires young geometers to pull together information they are currently learning with things they have learned previously. Here they rely on understanding something about parallel lines, alternative interior angles,...
Curated OER
Geometric Angles
Students explore angles and their use in Geometry. Students investigate three different kinds of angles: obtuse, acute, and right angles through an online activity. They identify pairs of angles with special relationships: vertical,...
Curated OER
An Introduction to Angles
Students identify and create angles. In this angle measurement lesson plan, students use sticks to make models of angles, then measure and name each angle.
Curated OER
Does Your Field Measure Up
Students measure angles using a plane table kit. In this geometry lesson plan, students use trigonometric identities to find the values of the length of a football field.
Curated OER
Exploring Angle/Pair Relationships
Students find missing angles and sides of triangles. In this geometry lesson plan, students create intersecting lines to measure angles. They use Cabri Software to create virtual angles.
Curated OER
Angles in Standard Positions
Students identify positive and negative angles using the Unit Circle. In this pre-calculus lesson, students identify the different angles on a unit circle using the coordinate plane and the four different quadrants as a guide. They...
Curated OER
Angles, Lines and Transversals
Students identify and determine angle pair relationships. In this geometry activity, students identify different angles of parallel lines that are cut by transversals. They identify interior and exterior angles after watching a video.
Curated OER
Exploring Angle Pair Relationships
Students investigate the relationship between angles of triangles. In this geometry lesson plan, students identify properties of right and non-right triangles. They differentiate between vertical and supplementary angles.
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
Angle Action 1,2 and 3
Students investigate angles through construction. In this geometry instructional activity, students use a protractor to identify the measurement of an angle. They identify angles cut by a transversal and two parallel lines.
Curated OER
Angle Pairs
Students identify different angle pairs. In this geometry lesson, students identify the different angles of two parallel lines cut by a transversal. They identify the interior and exterior angles.
Curated OER
Unit Squares and Triangles
This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle...
Curated OER
Measuring the Earth
Students use principles of geometry to measure the circumference of the Earth. In this applied geometry lesson, students use mathematics to determine scientific information. They make measurements, calculate the central angle, and...
Curated OER
Secants, Tangents and Arcs
Students identify chords and angles. In this geometry lesson, students calculate the length of the chords inside and outside of-the circle. They differentiate between tangent and secant lines.
Curated OER
Triangle Sum Theorem
Tenth graders investigate the theorems of angles and lines to prove triagle sum theorem. In this geometry activity, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how...
Curated OER
Parallel and Perpendicular Lines
Tenth graders explore parallel and perpendicular lines. In this geometry lesson, 10th graders investigate the relationships associated with parallel lines and transversals, perpendicular lines, and the angles formed by these...
EngageNY
Rotations of 180 Degrees
What happens when rotating an image 180 degrees? The sixth lesson in the series of 18 takes a look at this question. Learners discover the pattern associated with 180-degree rotations. They then use transparency paper to perform the...
Curated OER
Transformations: Translations
Learners perform transformations and translations using polygons. For this geometry lesson, students perform transformations on a coordinate plane. They identify the image and pre-image of each figure.
Curated OER
Let the Sun Shine In: Energy Conservation
Students create a project applying their math skills as they discuss energy conservation. For this geometry lesson, students define vocabulary relating to the environment and energy conservation. They construct a building that allow lots...
Curated OER
Pythagorean Theorem
Students solve problems using the Pythagorean Theorem. In this geometry instructional activity, students identify the sides and angles of a right triangle. They find the different trigonometric ratios and solve using sine, cosine and...
Curated OER
Square Graphs
Learners identify the different properties of quadrilaterals. For this geometry-lesson, students define parallel sides and diagonals of polygons as they compare to a quadrilateral. They identify the methods to find the angles in a...