Learning how to prove theorems in geometry can be challenging. This resource explains what a proof is, and the different styles for proofs. It also contains links to web-based practice problems that help guide learners though example...

Students explore the concept of paragraph proofs. In this paragraph proofs lesson, students make flow charts of the process of getting ready for school. Students convert the flow chart to a paragraph proof. Students use geometric...

Even U.S. President James Garfield had his own proof of the Pythagorean Theorem! Pupils consider three different attempts at a geometric proof of the Pythagorean Theorem. They then select the best proof and write paragraphs detailing...

In this geometric proof worksheet, students compose 20 triangle congruency proofs. Students will decide if there is enough information in problems 1-6 to prove if any triangles are congruent. In problems 17 to 20, students use given...

Logical thinking is at the forefront of this jam-packed lesson, with young mathematicians not only investigating geometric concepts but also how they "know what they know". Through each activity and worksheet, learners wrestle with...

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

It's time to proof read! Pupils read and analyze proof paragraphs from a model essay. They then practice writing their own proof paragraphs to express an opinion about offshore oil drilling. 

Words of proof. Learners continue coding The Electric Motor by marking the first point in yellow and the second point in blue. They discuss the structure of the paragraphs by identifying transition words and evidence to support the given...

One of the basic properties of inscribed angles gets a triangle proof treatment in a short but detailed exercise. Leading directions take the learner through identifying characteristics of a circle and how they relate to angles and...

Can you prove it? Lead your class through the development of the Side Splitter Theorem through proofs. Individuals connect the ratio and parallel method of dilation through an exploration of two proofs. After completing the proofs,...

Learners separate things that just appear similar from those that are actually similar. A diagram of triangles is given, and then a variety of geometric characteristics changed and the similarity of the triangles analyzed. Because the...

Proofs are usually an intimidating assignment. An engaging lesson focused on geometric proofs may reduce the anxiety! Pupils choose between several triangle proofs to complete and work on completing them. The assignment also gives a...

Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This unit...

In this inscribed angles activity, 10th graders solve 13 various types of problems related to inscribed angles in geometry. First, they identify a circle illustrated and each arc of the circle. They, students find the measure of each...

In this congruent triangles worksheet, 10th graders solve 5 various types of geometry problems related to triangles. First, they draw and label triangles, indicating the additional pairs of corresponding parts that would have to be...

Tenth graders investigate the Pythagorean Theorem. Then they type up a formal paragraph proof of a proof of their choice.

In this thesis-proof graphic organizer worksheet, students fill in a thesis, and the supporting and refuting evidence. They write a conclusion paragraph on the lines provided below the organizer.

Let's get colorful! Scholars use the Painted Essay technique to analyze and color code the conclusion of a model essay. Working in small groups, pupils then write a conclusion paragraph for their draft editorials about offshore drilling. 

Without ever using the actual term, this exercise has the learner develop the key properties of the midsegment of a triangle. This task leads the class to discover a proof of similar triangles using the properties of parallel lines cut...

Students construct two-column proofs. In this geometry lesson, students use deductive reasoning and geometric properties to justify given geometric statements. Students compare and contrast proofs.

Working backwards can sometimes help you see a path to solving a problem. In this chapter, properites of quadrilaterials are proven by looking at flowcharts and working the probem backwards. Worked through examples are given, along with...

Students create tornado proof buildings.  In this weather lesson plan, students review tornadoes, discuss creation of tornado proof buildings, and learn about the Fujita Scale of Tornado Intensity.  Students research tornado proof...

Investigate the meaning of the Pythagorean Theorem through modeling. After comparing the area of the square of each side, individuals cut triangles and squares to facilitate the comparison.

This set of worksheets constitutes enough work and materials to be considered a lesson. They guide readers through a process of exploring characters and their motivations, and writing a paragraph about them. Here are seven handouts that...