Printables
Virginia Department of Education

High School Mathematics Geometry Vocabulary Word Wall Cards

For Teachers 9th - 10th
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...
Handout
Lockport City School District

Reasons for Geometric Statement/Reason Proofs

For Students 8th - 11th Standards
Stuck trying to remember the formal language of a geometric proof? Never fear, this handout has them all ready to go. The reasons are sectioned by topic so this handy guide is ready when you are to tackle those two column proofs. 
Lesson Plan
Curated OER

Angles

For Teachers 4th - 5th
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...
Unit Plan
Mathematics Vision Project

Module 6: Congruence, Construction, and Proof

For Teachers 8th - 10th Standards
Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This...
Lesson Plan
Texas Instruments

Properties of Parabolas

For Teachers 9th - 12th Standards
Explore the properties of parabolas in this instructional activity. Construct a parabola given a focus and a directrix on the Ti-Nspire. Write equations of parabolas in vertex form and determine the a value of a parabola given a focus...
Lesson Plan
Illustrative Mathematics

Two Wheels and a Belt

For Teachers 9th - 10th Standards
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...
Lesson Plan
EngageNY

Construct a Square and a Nine-Point Circle

For Students 9th - 10th Standards
Anyone can draw a square, but can you CONSTRUCT a square? Here is a resource that challenges math scholars to create steps to finish their own construction. They test their ability to read and follow directions to complete a construction...
Activity
Curated OER

Inscribing a Square in a Circle

For Teachers 9th - 11th Standards
Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...
Lesson Plan
Curated OER

Points, Lines, Planes, and Space

For Teachers 9th - 12th
In this points, lines, planes, and space worksheet, learners solve word problems dealing with points, lines, planes, and space. Students complete 20 individual problems and 20 group problems.
Lesson Plan
Illustrative Mathematics

Area of a Trapezoid

For Teachers 7th - 9th Standards
Here is a straightforward example of how to apply the Pythagorean Theorem to find an unknown side-length of a trapezoid. Commentary gives additional information on proving that the inside of the trapezoid is a rectangle, but is...
Lesson Plan
EngageNY

Equations for Tangent Lines to Circles

For Teachers 9th - 12th Standards
Don't go off on a tangent while writing equations of tangent lines! Scholars determine the equations for tangent lines to circles. They attempt both concrete and abstract examples, such as a tangent line to the unit circle through...
Lesson Plan
EngageNY

Triangle Congruency Proofs (part 1)

For Teachers 9th - 10th Standards
Can they put it all together? Ninth graders apply what they know about proofs and triangle congruence to complete these proofs. These proofs go beyond the basic triangle congruence proofs and use various properties, theorems, and...
Unit Plan
Mathematics Vision Project

Module 2: Congruence, Construction and Proof

For Teachers 9th - 12th Standards
Construct yourself a winning geometry unit. A set of lessons introduces geometry scholars to constructions and proofs with compasses and straightedges. It also covers triangle congruence through transformations. This is the second of...
Unit Plan
Mathematics Vision Project

Module 6: Trigonometric Functions

For Students 9th - 12th Standards
Create trigonometric functions from circles. The first lesson of the module begins by finding coordinates along a circular path created by a Ferris Wheel. As the lessons progress, pupils graph trigonometric functions and relate them to...
Activity
Curated OER

Unit Squares and Triangles

For Teachers 9th - 11th Standards
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...
App
Bytes Arithmetic

Geometry Pad+

For Students 6th - 10th Standards
Graphing paper, pencil, ruler, protractor, and compass, all get replaced or supplemented with this dynamic geometry application. Here, you can create, move, and scale many different shapes, as well as, explore and change their properties...
Lesson Plan
EngageNY

The Definition of a Parabola

For Students 10th - 12th Standards
Put together the pieces and model a parabola. Learners work through several examples to develop an understanding of a parabola graphically and algebraically. 
Lesson Plan
EngageNY

Mid-Module Assessment Task - Geometry (Module 1)

For Teachers 9th - 10th Standards
How do you prepare class members for the analytical thinking they will need in the real world? An assessment requires the higher order thinking they need to be successful. The module focuses on the concept of rigid transformations...
Unit Plan
EngageNY

Complex Numbers and Transformations

For Teachers 11th - 12th Standards
Your learners combine their knowledge of real and imaginary numbers and matrices in an activity containing thirty lessons, two assessments (mid-module and end module), and their corresponding rubrics. Centered on complex numbers and...
Assessment
Inside Mathematics

Quadrilaterals

For Teachers 9th - 12th Standards
What figure is formed by connecting the midpoints of the sides of a quadrilateral? The geometry assessment task has class members work through the process of determining the figure inscribed in a quadrilateral. Pupils use geometric...
Lesson Plan
EngageNY

Pythagorean Theorem, Revisited

For Students 8th Standards
Transform your pupils into mathematicians as they learn to prove the popular Pythagorean Theorem. The 16th lesson in the series of 25 continues by teaching learners how to develop a proof. It shows how to prove the Pythagorean Theorem...
Lesson Plan
Curated OER

Define Geometry Terms

For Teachers 3rd - 5th Standards
The Common Core is intended to help all children meet high academic standards. Here is a Common Core designed lesson that is intended for learners with communication or language difficulties. The lesson is written in a narrative style...
Lesson Plan
Curated OER

Reflections and Equilateral Triangles II

For Teachers 9th - 10th Standards
Given the lines of symmetry in an equilateral triangle, your learners find where the pre-image vertices are mapped onto the new image. They explore the properties of equilateral triangles, the impact of reflections, and the...
Lesson Plan
Willow Tree

Midpoint and Distance Formulas

For Students 8th - 11th Standards
The shortest distance between two points is a straight line. Learners use the Pythagorean Theorem to develop a formula to find that distance. They then find the midpoint using an average formula.