Is the amount of information getting overwhelming for your geometry classes? Use this strategy as a way to organize information. The resource provides a handout of information studied in relation to triangle congruence. It includes a...

Young mathematicians rotate, flip, and sort their way to an understanding of the different attributes of geometric figures. Using transparent yellow and blue shapes, children try to match congruent figures together...

Young geometers become pool sharks in this analysis of the angles and lengths of a trick shot. By using angles of incidence and reflection to develop similar triangles, learners plan the exact placement of balls to make the shot....

If both pairs of opposite sides of a quadrilateral are congruent, is the quadrilateral a parallelogram? This task asks learners to determine the answer and to support their answer with a proof. The resource includes a commentary for...

Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...

Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet. 

For this geometry worksheet, students identify parallel lines, examine and interpret diagrams, and find the value of corresponding angles and lines.  This one-page worksheet contains 6 multiple-choice problems.  Answers are...

Just what does it take to show two rhombuses are similar? The assessment task asks pupils to develop an argument to show that given quadrilaterals are rhombuses. Class members also use their knowledge of similar triangles to show two...

In this postulates and theorems worksheet, students explore a concept map containing information about angles and sides, alternate interior angles, and diagonals of a parallelogram.  They use the concept map to prove theorems...

There are many different ways to show a proof of the Pythagorean Theorem.  Here is a nice hands-on paper cutting activity that shows a graphic representation. You can even challenge your young Pythagoreans to come up with their own...

This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle...

In this proving lines parallel activity, 10th graders solve 10 different types of problems that prove that various lines are parallel to each other. First, they find the value of x so that line a is parallel to line b. Then, students...

 In this geometry worksheet, students construct lines that are parallel and perpendicular forming different angles. They differentiate between interior and exterior angles. Students identify the angles formed by a transversal and...

Having a good working knowledge of math vocabulary is especially important for geometry learners. Here are 119 pages worth of wonderfully constructed definitions, constructions, formulas, properties, theorems, and postulates. This is a...

What figure is formed by connecting the midpoints of the sides of a quadrilateral? The geometry assessment task has class members work through the process of determining the figure inscribed in a quadrilateral. Pupils use geometric...

Pupils work in pairs to investigate what it takes to prove that two triangles are similar. They work through various shortcuts to find which are enough to show a similarity relationship between the triangles. Small groups work with the...

Geometric figures are perfect to use for proofs. Scholars prove conjectures about whether given points lie on a triangle and about midpoints. They use a provided dialogue among fictional learners to frame their responses.

Create the ultimate miniature golf course. The 93-page model curriculum unit from the Massachusetts Department of Elementary and Secondary Education contains nine lessons on understanding similarity in terms of both Euclidean geometry...

Students talk about mathematical language.  In this talking about your name lesson plan, students use the letters in their own name to review math vocabulary and concepts.  

Students explore the concept of polygon properties. In this polygon properties lesson plan, students draw polygons with different numbers of sides such as pentagons, octagons, hexagons, etc. Students identify different geometric shapes...

Eighth graders are presented with a labeled drawing of two parallel lines intersected by a transversal line. They are asked to discuss congruency of angles when the picture is rotated about a point on the transversal. Aligns with 8.G.A.5.

[Free Registration/Login may be required to access all resource tools.] Use alternate interior angles to determine angle congruency and the presence of parallel lines.

Consider two parallel lines that are intersected by a transversal, and when it crosses the two others, many different angle pairs are formed. See the special properties of the angle pairs in this interactive.

This tutorial provides a definition of corresponding angles and additional information is provided on angles.