Proof by Contradiction Teacher Resources

In this proofs by contradiction instructional activity, students solve 1 word problem about a crime.  Students use proof by contradiction to determine the criminal in the word problem.

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

Non-terminating. Non-recurring decimal. Irrational numbers. Proof by Contradiction? Root 2, 3, 5, 6, 7, 8. Don't be afraid to explore the impossible and check out this short video that offers a rational explanation of irrational numbers.

Viewers of a short video use the Proof by Contradiction technique; to determine which apprentice monk swallowed which crystal the group attempted to steal from the Sacred Crystal Temple.

Students explore the concept of vertex-edge graphs.  In this vertex-edge graphs lesson, students try to construct a graph with a given diameter, number of vertices, size, and planarity.  Students construct various vertex-edge graphs with...

Try as you might, some functions just cannot be computed. The lab introduces the class to the possibility of unsolvable problems. The fourth lesson in a series of seven begins with a logic problem, then progresses to looking at functions...

Perfect cloning is impossible — and that's been proven mathematically. Investigate the complexity of cloning in physics. The video instructor explains why cloning is theoretically impossible. He uses several examples to illustrate the...

Participants who use this resource will apply the Pythagorean Theorem to show whether or not the shaded triangle inscribed in a rectangle is a right triangle. Once all of the sides on the shaded triangle are found, it is important that...

Students engage in a lesson that is about the classification of triangles and the mathematical proofs involved in working with them. They work on a variety of problems that are created by the teacher with the focus upon the importance of...

Students research Babylonian mathematics. They calculate simple surd numbers. Students find the fractional form of rational numbers expressed as decimals. They work with numbers in base 60.