Curated OER
Basic Geometry ... A Pathway to Angles
Help 9th graders identify lines, points, rays, and planes in geometry. They practice identifying, measuring, and drawing angles of different degrees. This is a fundamental lesson to help students learn the building blocks of geometry.
Curated OER
Angles
Fourth and fifth graders investigate angles and name them according to the criteria for obtuse, acute, and right angles. They examine a human-made yarn pattern on the floor of their classroom and identify angles, vertices, and types of...
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
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...
Curated OER
Angles
Learners identify obtuse and acute angles in comparsion to a right angle. They identify obtuse, acute, and right angles. Pupils use "Shape Measure" to construct obtuse, acute, and right angles. They review line segements to locate right...
Curated OER
Twenty-Five Measures of the Angles of a Triangle Problems
In this triangle worksheet, pupils calculate the measures of the angles or the sums of the measures of the angles in twenty-five triangle problems and hands-on activities. The solutions are provided.
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history lesson plan 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...
EngageNY
Unknown Angle Proofs—Proofs with Constructions
Provide your emerging mathematicians with the tools to learn as they incorporate auxiliary lines to solve unknown angle proofs in this continuing segment. They decipher information from a diagram to uncover the missing pieces and...
Curated OER
Forming, Measuring and Labeling Angles
Pupils draw and measure angles. In this angle measurement lesson, the teacher demonstrates how to form and measure angles while explaining the parts of an angle, then students practice.
Curated OER
Sample Lesson Plan on Lines and Angles
Student complete worksheet using the definitions of lines and angle vocabulary. They define the word and follow a direction given on the worksheet such "construct a line." They complete an online tutorial on how to measure angles using a...
Curated OER
Interactivate - Lines, Rays, Line Segments, and Planes
Learners explore lines, rays, line segments, and planes. In this math lesson, students discuss the math concepts and direct their instructor in graphing functions. Learners collaborate in graphing additional functions.
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...
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...
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.
EngageNY
How Do Dilations Map Angles?
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure.
Curated OER
Measuring Angles & Segments
Young scholars view a PowerPoint for a warm-up lesson plan. They practice measuring around the classroom, measuring such things as the length and width of a desk, pencil, door, and book. Students use a website to practice measuring angles.
Curated OER
Measuring Angles
Sixth graders identify and measure right, acute, obtuse, and straight angles. In this geometry lesson, 6th graders review the definition of each angle and are shown examples of each specific angle. Students use toothpicks, gumdrops, and...
Curated OER
Midpoint of a Segment
Learners revisit midpoint and segments by graphing on the TI or computer. This activity can be done with pencil and paper, but is more interactive if it is done on a TI-navigator.
Texas Instruments
Investigating Segments in a Quadrilateral
Investigate the properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral. In this properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral lesson, students use...
Curated OER
Angles, Triangles, Quadrilaterals, Circles and Related
Students classify angles. In this angles lesson plan, students explore the characteristics of angles, triangles, quadrilaterals and circles. They identify polygons and sing a classifying angles song. Students participate in a...
Curated OER
Mr. Bo Jangle, What's Your Angle?
Third graders explore angles. In this geometry lesson plan, 3rd graders identify and define acute, obtuse, and right angles. Students form angles with their bodies, find angles in picture books, and record angles found outside in their...
Virginia Department of Education
Side to Side
Congruent figures: two figures that want to be just like each other. Individuals learn to distinguish between figures that are congruent and those that are not. Measuring the lengths of line segments and angles helps in this endeavor.
EngageNY
Fundamental Theorem of Similarity (FTS)
How do dilated line segments relate? Lead the class in an activity to determine the relationship between line segments and their dilated images. In the fourth section in a unit of 16, pupils discover the dilated line...
Curated OER
Angles: Angles, Angles, Everywhere
Students practice estiminating and measuring angles. After watching a short video, they identify angles in objects in the classroom and their homes. In groups, they participate in activities in which they are given a scenerio and are...