Learners calculate the sides of right triangles in this trigonometric ratios lesson. They use Cabri Jr. software and TI-83 or TI-84 calculators to find the side lengths and their ratios to each other for various triangles. The provided...

Students identify the properties of an isosceles triangle. In this geometry lesson plan, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.

Students identify the properties and theorems of triangles. In this geometry lesson, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.

Learners study parallel and perpendicular lines. In this parallel and perpendicular lesson, pupils explore 2-D shapes and determine if the sides are parallel or perpendicular.

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...

Using the Pythagorean Theorem to solve for missing angles, students evaluate right triangles and their properties.

Eighth graders label and define geometrical lines and angles. They identify angles on the board as acute, obtuse, straight, or right. In groups, 8th graders build with masking tape on the wall a pair of parallel lines, and a transverse...

Use this comprehensive pre-instruction assessment tool to focus your teaching where your class needs it most. Multiple choice questions assess your budding geometers' conceptual and vocabulary knowledge, but they do not solve any...

Seventh graders build their own Clinometer and using the tangent of angles, estimate the height of trees. Then these students develop and lesson to show whole class and determine the tallest tree on school property.

Pupils engage in an activity where one partner reads directions while the other follows those directions to complete a math task (such as bisecting an angle). As a reflection, they examine products to see what information the best...

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...

Students construct tesselations that fosters their ability to create, transform, and critique their own piece of work. This allows them to become aware of repeated patterns in math, and connect these patterns to artwork.

How do you prepare class members for the analytical thinking they will need in the real world? An assessment requires the higher order thinking they need to be successful. The module focuses on the concept of rigid transformations...

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...

Middle and high schoolers investigate all the different places in math that square root is present. In this geometry lesson, pupils discuss square roots as it relates to a right triangle and construction. They go over altitude, rise,...

Compare and contrast the four types of transformations through constructions! Individuals are expected to construct the each of the different transformations. Although meant for a review, these examples are excellent for initial...

Quadrilaterals can be quirky! Fourth graders use geoboards and bands to create four-sided figures. They analyze the attributes such as angle size and presence of parallel sides. As a result they learn to differentiate among...

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...

If you set up a triad of mirrors into a corner figuration, they act as a kaleidoscope, bouncing light waves back and forth indefinitely, changing the light that your eyes perceive. Although the materials required are very specific and...

Build on the understanding of finding angles using trigonometric ratios. Pupils develop the definitions of inverse trigonometric functions by restricting their domains in the 13th lesson of a 16-part series. They use inverse functional...

As part of their study of the influence of TV and films, class members consider how music, lighting, costumes, camera angles, etc. are used to influence the response of viewers.

Bridges rely on tension and compression to keep them standing. Pairs test this principle by constructing simple bridges and applying a force to the center. Teams use the provided activity to record their observations of the...

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. 

Scientists could measure the diameter of the sun before they knew its distance. Scholars construct a simple mirror box to measure the diameter for themselves. They compare this measurement with the official size, listed in a...