Virginia Department of Education
High School Mathematics Geometry Vocabulary Word Wall Cards
Having a good working knowledge of math vocabulary is especially important for geometry learners. Here are 119 pages worth of wonderfully constructed definitions, constructions, formulas, properties, theorems, and postulates. This is a...
Illustrative Mathematics
Shortest Line Segment from a Point P to a Line L
One of the hardest skills for many young geometers to grasp is to move beyond just declaring obvious things true, and really returning to fundamental principles for proof. This brief exercise stretches those proving muscles as the...
Curated OER
Tangent Lines and the Radius of a Circle
Your Geometry learners will collaboratively prove that the tangent line of a circle is perpendicular to the radius of the circle. A deliberately sparse introduction allows for a variety of approaches to find a solution.
EngageNY
Dilations as Transformations of the Plane
Compare and contrast the four types of transformations through constructions! Individuals are expected to construct the each of the different transformations. Although meant for a review, these examples are excellent for initial...
Curated OER
Tennis Balls in a Can
Make your classroom interesting by teaching or assessing through tasks. Deepen the understanding of Geometry and motivate young mathematicians. The task uses investigation with tennis balls and their container to prompt learners to...
Curated OER
Practice: Word Problems
Congratulations, you've just hit the word problem jackpot! Covering an incredible range of topics from integers and fractions, to percents, geometry, and much more, this collection of worksheets will keep young mathematicians...
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...
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...
EngageNY
Properties of Tangents
You know about the tangent function, but what are tangent lines to a circle? Learners investigate properties of tangents through constructions. They determine that tangents are perpendicular to the radius at the point of tangency,...
Curated OER
Pythagorean Theorem
In this Pythagorean theorem worksheet, 9th graders solve and complete 8 different types of problems. First, they go to the given website and copy the picture shown. Then, students draw a right triangle using the straight line between 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
General Pyramids and Cones and Their Cross-Sections
Are pyramids and cones similar in definition to prisms and cylinders? By examining the definitions, pupils determine that pyramids and cones are subsets of general cones. Working in groups, they continue to investigate the relationships...
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
Linear/Planar Geometry - Week 5
In this plane geometry worksheet, students combine the basis of plane geometry and linear problems to solve problems. They determine total surface area, the length of a line, and the sum of the edges of a three-dimensional figure. This...
Curated OER
Planes and Lines
In this geometry worksheet, learners identify the plane that passes through a point and define the theorem that represents parallel and perpendicular lines. There is an answer key.
EngageNY
Writing the Equation for a Circle
Circles aren't functions, so how is it possible to write the equation for a circle? Pupils first develop the equation of a circle through application of the Pythagorean Theorem. The activity then provides an exercise set for learners to...
EngageNY
Criterion for Perpendicularity
The Pythagorean Theorem is a geometry pupil's best friend! Learners explain the equation a1b1 + a2b2 = 0 for perpendicular segments using the Pythagorean Theorem. They are able to identify perpendicular segments using their...
EngageNY
Lines That Pass Through Regions
Good things happen when algebra and geometry get together! Continue the exploration of coordinate geometry in the third instructional activity in the series. Pupils explore linear equations and describe the points of intersection with a...
Illustrative Mathematics
Slopes and Circles
An upper-level treatment of what is often presented as a basic concept (the right angle of an inscribed circle on the diameter), this activity really elevates the mathematical thought of the learner! Expected to develop formulas...
Curated OER
Perpendicular Bisector Theorem
High schoolers construct perpendicular bisectors using Cabri Jr. on their graphing calculator. They then construct conditional statements about perpendicular bisectors along with their converse, inverse, and contrapositive.
Curated OER
Application of Properties of Quadrilaterals in the Coordinate Plane
Students apply definitions and theorems to verify special quadrilaterals
using coordinate geometry. They apply the slope formula, the midpoint
formula, and the distance formula to justify that a given quadrilateral is a
parallelogram....
Curated OER
Preparation and Transition to Two-Column Proofs
Young scholars investigate proofs used to solve geometric problems. In this geometry lesson, students read about the history behind early geometry and learn how to write proofs correctly using two columns. The define terminology valuable...
Curated OER
Applications of Properties of Quadrilaterals in the Coordinate Plane
Students explore the concept of quadrilaterals. For this quadrilaterals lesson, students use the slope formula, midpoint formula, and distance formula to justify that a given quadrilateral is a parallelogram.
EngageNY
Comparing the Ratio Method with the Parallel Method
Can you prove it? Lead your class through the development of the Side Splitter Theorem through proofs. Individuals connect the ratio and parallel method of dilation through an exploration of two proofs. After completing the proofs,...