Proofs Teacher Resources

Enjoy this nicely organized worksheet that puts together multiple problems regarding trapezoid proofs. The resource can be used as a guide that begins with proving properties and ends with solving for measures of line segments.

In this right triangles worksheet, 10th graders solve 5 problems that relate to different right triangles. First, they find the values of x and y so that each triangle is congruent to the other. Then, students write a two-column proof...

In this geometry worksheet, students identify the missing angles formed by parallel lines and a transversal. They differentiate between parallel and perpendicular lines. There are four questions.

You've investigated relationships between chords, radii, and diameters—now it's time for arcs. Learners investigate relationships between arcs and chords. Learners then prove that congruent chords have congruent arcs, congruent arcs have...

A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...

In this geometric quiz activity, students complete 5 problems involving segment addition, distance formula, and solving equations.

In this lines and angles learning exercise, 10th graders solve and complete types of problems that include different line segments and angles to identify. First, they determine whether each line is parallel, skew, or perpendicular in the...

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...

Connect algebra and geometry on the coordinate plane. The eighth unit in a nine-part integrated course has pupils develop the distance formula from the Pythagorean Theorem. Scholars prove geometric theorems using coordinates...

Students analyze a drawing of a regular octagon inscribed in a circle to determine angle measures, using knowledge of properties of regular polygons and the sums of angles in various polygons to help solve the problem. They use...

In this tests for parallelograms worksheet, 10th graders solve 7 various types of geometry problems that include parallelograms. First, they determine if each quadrilateral is a parallelogram and justify their answers. Then, students...

In this congruent triangles worksheet, 10th graders solve and complete 10 different problems to determine whether each set of triangles is congruent or not. First, they copy each diagram onto a piece of paper and mark up the paper with...

In this geometry practice problems activity, students write geometric proofs to prove the validity of given circumstances. Students prove parallel lines, perpendicular lines, and similar angles. This four-page activity contains eight...

Learners classify triangles and make connections regarding angle measurements and attributes of acute, right, and obtuse triangles. They listen to teacher define and explain triangles. Everyone imagines a place where a broken wing for a...

This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...

High schoolers investigate the usage of parallel and perpendicular shapes in the real world. In this geometry lesson, students investigate shapes for properties that are related to the real world. They relate all the properties of shape...

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...

Young scholars, as a final project, draw a picture of their ideal neighborhood on a sunny day. In addition to the sun, their drawings include homes, trees, streets, and selected objects. Each object in their drawing has a written...

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...

Lead your class on an exciting journey through the world of math as they review geometry facts and solve for unknown angles. They learn how to use auxiliary lines and congruent angles to correctly complete each practice problem...

This unit on connecting algebra and geometry covers a number of topics including worksheets on the distance formula, finding the perimeter and area of polynomials, the slope formula, parallel and perpendicular lines, parallelograms,...

Scholars first investigate relationships in the side lengths of 30°-60°-90° triangles and 45°-45°-90° triangles. This knowledge then helps them solve problems later in the instructional activity about special right triangles.

The Pythagorean Theorem is a geometry pupil's best friend! Learners explain the equation a1b1 + a2b2 = 0 for perpendicular segments using the Pythagorean Theorem. They are able to identify perpendicular segments using their...

Students prove conjectures about geometric figures on the plane or in space using coordinate geometry. They develop fluency in operations with real numbers, vectors and matrices using mental computation or paper-and-pencil calculations...