Is that a right triangle or a wrong triangle? Young mathematicians look at eleven different shapes and use a measuring tool of their choice to determine which triangles have right angles. Consider cutting out sets of the shapes to...

Examine the relationship between time and geometry. A series of five lessons provides a grade-appropriate problem from elementary through high school. Each problem asks learners to compare the movement of the hands on a clock to an angle...

Four triangles are depicted for learners to construct on a geoboard. They compute and compare the areas, and so meet one of the sixth grade Common Core standards for geometry. Note that the set of triangles does not include a right...

Are you tired of answers without understanding? Learners can give a correct response, but do they really understand the concept? Have young mathematicians think deeper about linear functions, angles, and formulas in algebra....

What makes an equilateral triangle equilateral? It turns out it's much more than just the side lengths! Learners analyze four different triangles to determine the best equilateral triangle. They create a formula that they later use to...

The class gets to practice being a mathematician in ancient Greece, performing geometric application problems in the way of Eratosthenes. After following the steps of the great mathematicians, they then compare the (surprisingly...

Life science learners discover the range of peripheral vision. They compare the angles at which they can detect motion, colors, and detailed shapes. 

Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...

Using NASA's Live Access Server, earth scientists compare the temperature, precipitation, and normalized difference vegetation index for four different locations. They use the data to identify the climate zone of each location using...

Design and build a rover ... then eat it? This activity has groups of two design and build Mars rovers. The teams determine what instruments they want to include with their rover and plan a budget. They calculate the cost of the body of...

Make music. Class members construct a simple record player using a paper cone and a pin. The resource provides a description of what is happening and why listeners can hear the sounds through the cone. 

This collaborative activity investigates the meaning of a trapezoid and a parallelogram. It begins by presenting two different definitions of a trapezoid. Learners are to reason abstractly the difference between the two definitions and...

Discover how to program objects to move on a screen. In the second lab of a five-part unit, each learner uses block instructions to program a sprite to follow their mouse (cursor). They investigate how to use these same block...

The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...

This activity is a follow-on activity to inscribing a square in a circle. The overall problem is more complex. It deals with geometric constructions, properties of triangles, and regular hexagons. The final part of the activity...

Japan's Taisho Period was a time when authors like Akutagawa and other Japanese modernists began to experiment with point of view and literary form, making the literature produced during this time period a natural choice for teaching...

Students learn various topics associated with the circle through studying a clock. Topics include reading analog time, understanding the concept of rotation (clockwise vs. counter-clockwise), and identifying right angles and straight...

Students use inclined planes as they recreate the difficult task of raising a monolith of rock to build a pyramid. They compare the push and pull of different-sized blocks up an inclined plane, determine the angle of inclination, and...

Explore sine, cosine, and tangents compared to the selected angle.

Students, teachers, and parents alike will enjoy this challenging math site. It contains a clever brain teaser section plus creative problems related to algebra, geometry, measurement, numbers, statistics, and probability. A Spanish...

Using Cabri Jr, the students (with the teachers help) will create parallel lines cut by a transversal, measure angles, and compare the relationships of the angles formed using features of the Cabri Jr.

Test your mathematical aptitude with challenge exploring the concepts of measurement and geometry. Find the area of the windshield wipers to figure out who sees better in the rain, car drivers or truck drivers. An activity from the NCTM...

In this activity, students will explore the concepts underlying the Triangle Inequality Theorem by comparing side lengths and angle measures of a triangle. They will use an interactive construction to see why this theorem is true.