What does it take to show two triangles are similar? The 11th segment in a series of 16 introduces the AA Criterion for Similarity. A discussion provides an informal proof of the theorem. Exercises and problems require scholars to apply...

Geometric volume calculations are brought into the real world in a quick set of application problems. Learners are asked to help a patient figure out how to drink a prescribed amount of water both at work and at home. This activity...

Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.

Add a little algebra to the geometry. Class members learn about the Addition Postulate for segments and angles. The pupils use their knowledge of solving equations to find lengths of segments and measures of angles. Individuals apply...

Building blocks have more uses than simply entertaining children. Young mathematicians calculate the volume of a given cube, and then calculate the volume and surface area of a prism formed from multiple cubes.

Where can you see an aurora in North America? After completing an astronomy activity, scholars can locate the exact coordinates. Pupils plot points of the inner and outer ring of the auroral oval and answer questions based on...

Young scientists build on their previous knowledge and apply it to coronal mass ejections. By plotting the path of two different coronal mass ejections, they develop an understanding of why most don't collide with Earth.

Scholars can use area formulas, but can they apply what they know about area? The lesson challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and other...

It's all Greek to me. Scholars work a task that Greeks first formulated for an ancient math challenge. Provided with an angle and a point inside the angle, scholars develop conjectures about what is true about the shortest line segment...

Help the local elementary school fix their playground by calculating the amount of sand needed near the swing set. The problem practices setting up proportions and ratios with three different options for solving. You can chose the option...

Your geometry learners explore Angle-Side-Angle congruence in this collaborative task. The sum of the interior angles of all triangles being one hundred eighty degrees, is the key learners will discover as they explain their reasoning...

Make your classroom interesting by teaching or assessing through tasks. Deepen the understanding of Geometry and motivate young mathematicians. The task uses investigation with tennis balls and their container to prompt learners to...

How can baseball and skeet-shooting be modeled mathematically? Sports lovers and young mathematicians learn how to use quadratic equations and systems of equations to model the flight paths of various objects.

Is it a right triangle or not? Introduce scholars to the converse of the Pythagorean Theorem with a lesson plan that also provides a proof by contradiction of the converse. Pupils use the converse to determine whether triangles with...

Apply the Pythagorean Theorem to coordinate geometry. Learners find the distance between two points on a coordinate plane by using the Pythagorean Theorem. The vertical and horizontal change creates a right triangle, which allows...

Combine transformations and triangle congruence in a single activity. Scholars learn to view congruent triangles as a rigid transformation. Using triangle congruence criteria, learners identify congruent triangles and the rigid...

Double, toil ,and double linear dimensions. Learners first complete an assessment investigating how doubling linear dimensions affects the area of pizzas and the volume of popcorn containers. They then complete an activity investigating...

It is positive that how one performs on the first test relates to their performance on the second test. The three-question assessment has class members read and analyze a scatter plot of test scores. They must determine whether...

Introduce learners to set of complete instructions that describe how to build a magnetometer that works just like the ones professional photographers use to predict auroras. The diagrams are wonderfully descriptive, and the written...

Students familiarize themselves with the construct and measure menus. They demonstrate how to use the Sketchpad Calculator. They draw a triangle and construct the centroid. They shade in each of the small triangles and measure the area.

Students explore perimeter. In this geometry and measurement lesson, students create squares and rectangles using given perimeters. Students construct four sided shapes with given perimeters using the computer program "Math Keys:...

Students investigate ways to enhance an object's flying ability.  In this model construction lesson, students construct two paper airplanes, one of which is twice as big as the first.  Students compare and contrast the two...

High schoolers identify the volume of cones and pyramids. In this geometry lesson, students derive the formula for cones and pyramids. They calculate the volume of cones and other three dimensional shapes.

High schoolers will love this geometrically exact ceramics project; they create a personalized clay box using the slab method and mathematical measurements. They utilize scoring and square construction and can decorate the boxes to...