Can you follow a composition of transformations, or better yet construct them? Young mathematicians analyze the composition of dilations, examining both the scale factor and centers of dilations. They discover relationships for both...

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 lesson then provides an exercise set for learners to...

Students explore area and perimeter through coordinate geometry using student literature, hands-on manipulatives, and the Internet.

High schoolers investigate properties of the four centers of a triangle and explore a special property of the circumcenter and orthocenter of a triangle. This lesson plan requires the use of Cabri, Jr.

Students explore geometry using a Rubik's Cube. In this 2-D and 3-D shapes lesson, students use the Rubik's Cube to find the center, edge and corner pieces. Students then find the dimensions of the Rubik's Cube and read the solution...

Your geometry learners will discover and show the construction of the circumcenter of a triangle. Guided by the steps in the activity, they construct perpendicular bisectors of each side that have a point of concurrency called the...

When it comes to rating educational calculators, this calculator is always near the top of this list. Now it's available as an app. There is a lot of calculator power wrapped up in this app. Not only is this a fully functioning...

We landed on the moon with less computing capabilities than you can find in this app! Here is a multiple function calculator that takes all the power you get from a handheld and adds the wonderful large screen that only a tablet can...

Putting a rectangular object into a circular one—didn't the astronauts on Apollo 13 have to do something like this? Learners first construct the center of a circle using perpendiculars. They then discover how to inscribe a rectangle in a...

What does completing the square have to do with circles? Math pupils use completing the square and other algebraic techniques to rewrite equations of circles in center-radius form. They then analyze equations of the form x^2 + y^2 + Ax +...

Is that drawn to scale? Capture the artistry of geometry using the ratio method to create dilations. Mathematicians use a center and ratio to create a scaled drawing. They then use a ruler and protractor to verify measurements. 

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...

A diameter is the longest chord possible, but that's not the only relationship between chords and diameters! Young geometry pupils construct perpendicular bisectors of chords to develop a conjecture about the relationships between chords...

Learn transformations through constructions! Pupils use perpendicular bisectors to understand the movement of a reflection and rotation. They discover that the perpendicular bisector(s) determine the line of reflection and the...

Don't stuff money under your mattress. To find out why learners first complete a task determining how $24,000 in cash would affect the height of a mattress and whether this same amount would fit into a suitcase of given dimensions....

Students research how engineers and scientists generate linear and angular measurements with geometry to survey the Earth and Mars. They assess how geometric shapes affect navigation. A surveyor comes to the classroom and explains how he...

Students use the correct tool to measure distances. In this geometry lesson, students use an odometer and ruler correctly as they study maps. They describe how far way something is.

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...

Geometry students use hinged mirrors to discover that the regular polygons are composed of triangles tessellating around a center point. They sketch triangles on paper models of the regular polygons having 3 to 10 sides and compute the...

Geometry learners touch the surface of how a global positioning system works. The end goal is to find the intersections of three different spheres geometrically and algebraically given their algebraic representations.

Kindergartners listen to a story read by their teacher, then use magnetic shape pieces to construct simple designes. They "build" their own house using pre-cut paper shapes. This age-appropriate lesson would be an excellent choice for...

Just like a painting or the symbols on a flag, quilts can express ideas that reflect a cultural context, space, and time. The class discusses the history of quilt making throughout US history and what different types of quilts mean. They...

Tenth graders investigate dilations and explore the dilation transformation before investigating the properties of a dilation using Cabri Jr. Students extend the concept of dilatation to the coordinate plane.

There are an infinite number of points on a circle; can you find nine of them? After putting together a nine-point circle, pupils use constructions and their knowledge of triangle segments to determine the center of the circle. Learners...