Students investigate triangles and congruences. In this geometry lesson, students differentiate between inductive and deductive reasoning. They differentiate between similar and congruent triangles.

In this geometry activity, 10th graders write two-column and paragraph proofs to prove angle pair relationships.  The one page activity contains five problems.  Answers are not included. 

Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...

Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...

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...

What's so special about tangents? Learners first explore how if a circle is tangent to both rays of an angle, then its center is on the angle bisector. They then complete a set of exercises designed to explore further properties and...

In this triangle theorems instructional activity, students identify the theorem used to prove the specified triangular relationship. Students are shown an illustration of two or more triangles. They identify the postulate that would be...

In this geometry worksheet, students answer questions about triangles using the correct properties. They find missing angles and sides of triangles. There are 15 questions with an answer key.

In this polygons worksheet, 10th graders identify and define both a polygon and a convex polygon and then, they apply two theorems that involve the interior and exterior angles of a convex polygon. First, they find the sum of the...

In this properties of geometry worksheet, 10th graders solve and complete 12 different problems that include various theorems. First, they draw a figure that illustrates the SAS inequality property. Then, students prove that two line...

In this trapezoids learning exercise, 10th graders solve 5 different problems related to trapezoids and applying the appropriate theorem. First, they define a trapezoid, including its bases, legs, and base angles. Then, students use the...

Students view a right triangle displayed by the teacher. Students measure legs and the interior angles of the triangle. They look for a pattern or relationship between the legs and angles. Students use pegboards and string to create more...

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...

An outstanding lesson plan on triangles awaits your math scholars. Learners focus on the triangle, which is the strongest of all polygons. They see the role that triangles play in the design of buildings, and learn about triangle...

Students explore the application of Hinge Theorem. In this geometry lesson, students write inequalities, given two sides of a triangle. They solve problems with triangular inequalities using the proper theorem.

More than just a worksheet, the resource provides a thorough guide to navigate through the land of parallelograms. Filled with definitions and theorems, the resource supports learners through problems such as proofs and finding missing...

49Students investigate the properties of right triangles. In this geometry activity, students differentiate between similar and congruent triangles. They use the Pythagorean Theorem to find the missing angles and sides.

Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...

For this geometry worksheet, students solve problems using the similarity and congruent theorem. They find the vertices and different parts of polygons using theorems. There are 18 questions.

In this parallelograms worksheet, 10th graders identify and describe a quadrilateral, a diagonal, and a parallelogram in 7 different problems. First, they find the values of x, y, and z in each quadrilateral to prove that it is a...

Students investigate basic geometric concepts. In this geometry lesson, students explore solids through measuring and modeling. This assignment models the importance of understanding concrete objects in geometry.      

Students draw diagrams demonstrating how it is possible to two central angles to be congruent and their minor arcs are not congruent. In groups, they illustrate theorems with their constructed circles, create diameters of circles that...

In this geometry worksheet, 10th graders order the sides and angles of a triangle and determine the range of the third side of a triangle given the lengths of two sides.  The one page worksheet contains sixteen questions. ...

Ninth graders find the height of every day objects using techniques learned through postulates that allow triangles in a problem to be similar. They calculate the length of a missing side and solve proportions.