Curated OER
Triangle Inequality
Students discover that the sum of the lengths of any two sides of a triangle must be greater than the third side. They are shown how a triangle is formed using three strips such as that the triangle is seen inside the strips.
Mt. San Antonio Collage
Circles
Don't circle around the topic, but get right to the center with tons of practice regarding circles in geometry. The note-incorporated activity provides guided practice through many topics such as central angles, inscribed polygons...
Lane Community College
Review Sheets: Geometry
Full of problems with polygons, angles, lines, and triangles, your learners get a multi-page packet that provides all they need to know. It contains many of the standard problem types as well as some more challenging questions.
Curated OER
Math: Tangents
Students discover how to recognize tangents and how to use their properties. They investigate and use the properties of angles, arcs, chords, tangents, and secants. Students use two tangents and the properties of similar triangles to...
Curated OER
Angles and Similarity
High schoolers identify triangles as similar or congruent. In this geometry lesson, students drag triangles around on the navigator to see the effect of different angles on the shape of the triangle. They discuss angle similarity and...
Curated OER
Why Doesn't SSA Work?
Students investigate the relationship between angles and their sides. For this geometry lesson, students prove why SSA does not work as a true angle side relationship theorem.
Curated OER
Similar triangles
Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...
EngageNY
Conditions for a Unique Triangle—Three Sides and Two Sides and the Included Angle
Building on the previous lesson in the 29-part series, the ninth lesson asks individuals to construct a triangle given specific criteria. First, they are given three specific side lengths, followed by two sides and the included angle....
Curriculum Corner
8th Grade Math Common Core Checklist
Ensure your eighth graders get the most out of their math education with this series of Common Core checklists. Rewriting each standard as an "I can" statement, this resource helps teachers keep a record of when each standard was...
Illustrative Mathematics
Bank Shot
Young geometers become pool sharks in this analysis of the angles and lengths of a trick shot. By using angles of incidence and reflection to develop similar triangles, learners plan the exact placement of balls to make the shot....
Curated OER
Angles
Students measure angles using a protractor. In this geometry lesson, students solve for the missing angles using equations set to the theorem of triangles. They measure missing angles through construction and identify congruent angles.
Curated OER
Similar Triangles on the Coordinate Plane
Students investigate triangles and their properties. In this geometry lesson, students differentiate between similar and congruent triangles. They use the SSS theorem to help identify the triangles that are similar or congruent.
Curated OER
Trapezoids
In this trapezoids worksheet, 10th graders solve 5 different problems related to trapezoids and applying the appropriate theorem. First, they define a trapezoid, including its bases, legs, and base angles. Then, students use the...
Curated OER
Mathematics in Robotics
Students build and create using math. In this geometry lesson plan, students differentiate between congruent and similarity as they observe polygons. They create robots with different functions using properties of geometry.
Curated OER
Similar Triangles - Applied Problems
High schoolers differentiate between similar and congruent triangles. In this geometry instructional activity, students identify the angles of triangles using the similarity theorem. They apply concepts of triangles to the real world.
Curated OER
Triangle Fundamentals Homework
In this geometry worksheet, learners identify the missing angles of non right triangles using the angle sum theorem. They solve for the unknown using algebra. There are 21 questions.
Curated OER
Compass Designs
Students investigate the properties of two and three dimensional objects. In this geometry lesson, students differentiate polygons based on similarity and congruence. They make observation and interpret the data.
Curated OER
Triangles in Architecture
Students find triangles in the real world. In this geometry lesson plan, students analyze and identify properties of two and three-dimensional objects. They differentiate between similarity and congruence.
Curated OER
Measuring Body Angles
Learners use technology to graph and compare angles. In this geometry lesson, students range of motion in the environment. They identify the missing parts of polygons using similarity and congruence.
Curated OER
Analyzing Body Angles
Students investigate angles of polygons. In this geometry lesson plan, students identify the relationship between angles and the number of sides in a polygon. They differentiate between sumilarity anf congruence in angles and sides.
Curated OER
Studying Special Segments in Triangles
Students investigate special segments in triangles. In this geometry lesson, students graph, compare, estimate and predict findings based on their data. They differentiate between similarity and congruence of triangles.
Curated OER
Geometry and Measurement
Young scholars view a right triangle displayed by the teacher. Students measure legs and the interior angles of the triangle. They look for a pattern or relationship between the legs and angles. Young scholars use pegboards and string to...
Curated OER
Geometry: Angles
In this angle worksheet, students find the value for a given variable. They use similar figures, alternate interior angles, side angle side, and other geometric theorems and proofs to determine the value of the given variable. This...
Curated OER
Exploring Secants: Products of Segments
Students explore secants and circles. In this geometry instructional activity, students identify the properties of two and three dimensional shapes. They create arguments to prove the theorems are true.