High School geometers verify through experimentation certain properties about dilations. This multi-step problem challenges them to construct examples of dilations to verify specific facts, the final step provides an opportunity to more...

Learners see application of construction techniques in a short but sophisticated problem. Combining the properties of inscribed triangles with tangent lines and radii makes a nice bridge between units, a way of using...

Boxing takes on a whole new meaning! The second installment of the three-part series has groups create lidless boxes from construction paper that can hold the most rice. After testing out their constructions, they build a new box....

Need an activity for teaching the Pythagorean Theorem? Geometry juniors apply the Pythagorean theorem to two triangles to determine a final calculation. 

Challenge the spatial thinking of your young mathematicians with this printable tangram puzzle. Using different sized triangles, squares, and parallelograms, children must figure out how to fit all the shapes together to create a square.

Your geometry learners are guided by questions that help them use the language of reflections to explain the Side-Angle-Side congruence between two triangles in this collaborative task. Given a sample solution, declaring the...

While it may seem incredibly obvious to the geometry student that congruent sides make congruent triangles, the proving of this by definition actually takes a bit of work. This exercise steps the class through this kind of proof by...

Can you build it? Yes you can! This interactive game includes four design challenges presented on separate cards. The cards outline the challenges with limited restrictions but with an end goal in mind. The competitions include building...

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...

From the San Francisco 49er's Museum Education Program which promotes STEAM concepts, students construct a three dimensional (3-D) artifact stand that is the exact replica of "The Catch" which is 70 inches high. Emphasis is placed on...

This lesson offers an interesting, hands-on experience for middle school students studying cylinders. Students will create cylinders, and measure and compare their volumes.