Shodor Education Foundation
Triangle Area
While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...
EngageNY
An Area Formula for Triangles
Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....
Curated OER
Triangle Series
Your algebra learners emphasize the"geometric" in geometric series as they use a common ratio between algebraic terms and find that it corresponds to a repeated similarity transformation.
Education Development Center
Finding Triangle Vertices
Where in the world (or at least in the coordinate plane) is the third vertex? Given two coordinate points for the vertices of a triangle, individuals find the location of the third vertex. They read an account of fictional...
Illustrative Mathematics
Equal Area Triangles on the Same Base II
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
Doing Maths
Area of Various Shapes
Find the area of triangles, rectangles, and parallelograms using this metric worksheet.
Radford University
Finding the Largest Possible Area
If you want a bigger garden, here's a task for you. Given the perimeter of a triangular garden, scholars determine the largest possible area. They then generalize their findings and extend the idea to other polygons.
Curated OER
Exploring Number and Operation in Secondary Mathematics
Young geometers need a clear understanding of perimeter, volume, and area. This lesson provides a worksheet to help small groups of learners to calculate various measurements of objects and choose the proper units for measurement. It...
Virginia Department of Education
The Pythagorean Relationship
Add up areas of squares to discover the pythagorean relationship. Small groups create right triangles with squares along each side. They calculate the areas of each square and notice the relationship. Groups construct other types of...
EngageNY
The Binomial Theorem
Investigate patterns in the binomial theorem. Pupils begin by reviewing the coefficients from Pascal's triangle. They look at the individual terms, the sums of the coefficients on a row, and the alternating sum of each row. Individuals...
Radford University
Parallel Lines Cut by a Transversal
Use the parallel lines to find your way. After first reviewing geometric constructions and the relationships between angles formed by parallel lines and a transversal, young mathematicians write proofs for theorems relating to parallel...
EngageNY
Law of Cosines
Build upon the Pythagorean Theorem with the Law of Cosines. The 10th part of a 16-part series introduces the Law of Cosines. Class members use the the geometric representation of the Pythagorean Theorem to develop a proof of the Law of...
PBS
Accessible Shapes
All the 2-D and 3-D measurement work you need is in one location. Divided into three sections, the geometry lesson plans consist of visualization of three dimensions, classifying geometric figures, and finding surface area and volume....
Geometry Accelerated
Coordinate Geometry Additional Practice
Your learners get extra practice using coordinates in calculating mid points, finding end points, deciding if points are collinear, calculations using slope concepts, writing linear equations, using triangles and quadrilaterals, and...
Mathematics Vision Project
Module 7: Modeling with Geometry
Model good modeling practices. Young mathematicians first learn about cross sections and solids of revolution. They then turn their attention to special right triangles and to the Laws of Sine and Cosine.
Radford University
2 and 3 Dimensional Shapes
Take a similar approach to three dimensions. Pupils develop the relationship between areas of similar objects and see how they relate to the ratio of the sides. Building upon area formulas, small groups put together volume formulas for...
DiscoverE
Dome Home
Homes come in many different shapes and sizes. Building a model of a geodesic dome is the ultimate goal for the activity. Cutting and folding is the way to go here.
Calvin Crest Outdoor School
Survival
Equip young campers with important survival knowledge with a set of engaging lessons. Teammates work together to complete three outdoor activities, which include building a shelter, starting a campfire, and finding directions in the...
Math Stars
Math Stars: a Problem-Solving Newsletter Grade 7
Put on your thinking caps because middle school math has never been more interesting in this huge resource full of thought provoking questions. Written as a newsletter, the resource has 10 two-page newsletters with a variety of...
EngageNY
The Volume Formula of a Pyramid and Cone
Our teacher told us the formula had one-third, but why? Using manipulatives, classmates try to explain the volume formula for a pyramid. After constructing a cube with six congruent pyramids, pupils use scaling principles from previous...
Illustrative Mathematics
Shape Hunt Part 2
Shapes are everywhere in the world around us, from rectangular doors to the circular wheels of a car. The second lesson plan in this series opens the eyes of young mathematicians to this wonderful world of shapes as they search the...
Exploratorium
Beyond Dominoes: Polyominoes
Dominoes, polyominoes, tetrominoes, and pentominoes are the subject of this interesting math activity designed for middle schoolers. Pupils cut out shapes that are embedded in a worksheet in the plan, and experiment with them by taping...
EngageNY
Complex Numbers and Transformations
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...
Beauty and Joy of Computing
Building Your Own Blocks
Isn't building with blocks an activity for toddlers? The third lab of a five-part unit teaches young computer scientists how to create their own block instructions for programming. They use these blocks to create geometric figures, spell...