Worksheet
Curated OER

Proofs in Coordinate Geometry

For Students 10th - 11th
In this coordinate geometry instructional activity, students identify the lengths of a quadrilateral and find the slope of a line. They use proofs to identify the characteristics of given quadrilaterals. This one-page instructional...
Worksheet
Curated OER

Congruent Triangles

For Students 10th
In this congruent triangles worksheet, 10th graders solve and complete 10 different problems that include various forms of triangles. First, they name the method for proving each set of triangles congruent using the given information....
Assessment
Math Worksheets Center

Congruent Triangle Proofs Quiz

For Students 9th - 12th
A congruent triangles quiz challenges teenage mathematicians to complete a pair of geometric proofs. Each problem includes a picture of the triangles in question, a given set of information, and the five steps needed to finish the proof....
Worksheet
Curated OER

Congruent Triangles

For Students 10th
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...
Worksheet
Curated OER

Proofs Involving Congruent Angles

For Students 11th - 12th
For this congruent triangle worksheet, students write proofs to support characteristics of congruent triangles. This one-page worksheet contains ten problems.
Lesson Plan
EngageNY

The Converse of the Pythagorean Theorem

For Teachers 8th Standards
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...
Lesson Plan
Virginia Department of Education

Pythagorean Theorem

For Students 8th Standards
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.
Worksheet
Curated OER

Triangle worksheets

For Students 10th
In this geometry worksheet, 10th graders explore triangle properties, including the sum of the measures of the angles of a triangle, the triangle inequalities, properties of isosceles triangles, properties of congruent triangles, and...
Worksheet
Curated OER

More Congruent Triangles

For Students 10th
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...
Worksheet
Curated OER

Proofs with Triangles

For Students 9th - 12th
In this geometry worksheet, high schoolers prove triangle congruence by making statements with reasons and concluding with the AAS or HL theorem. There are 2 proofs.
Worksheet
Curated OER

Congruent Triangles

For Students 10th
In this geometry worksheet, 10th graders identify the corresponding parts of congruent triangles.  The one page worksheet contains four problems.  Answers are not provided. 
Activity
Illustrative Mathematics

Reflections and Isosceles Triangles

For Teachers 9th - 11th Standards
Geometers explore symmetries of isosceles triangles by using rigid transformations of the plane. They complete four tasks, including congruence proofs, which illustrate the relationship between congruence and rigid transformations. The...
Worksheet
Curated OER

Indirect Euclidean Proofs

For Students 10th
In this Euclidean proofs worksheet, 10th graders solve 10 different problems that include completing indirect Euclidean proofs. First, they write a statement for each of the reasons listed on the sheet of proofs. Then, students solve the...
Worksheet
Curated OER

Quiz: Beginning Congruent Triangle Proofs

For Students 10th - 11th
In this congruent triangle proof worksheet, students write theorems to prove the congruence of given triangles. This one-page worksheet contains three given polygons to prove congruence.
Worksheet
Curated OER

Indirect Euclidean Proofs

For Students 7th - 8th
In this indirect Euclidean proof worksheet, students write statements supporting the reasons for a given proof. This one-page worksheet contains ten problems.
Lesson Plan
EngageNY

Ptolemy's Theorem

For Teachers 9th - 12th Standards
Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.
Worksheet
Curated OER

Proofs with Triangles

For Students 9th - 10th
For this geometry worksheet, student solve problems with triangles using proofs. They identify the solution based on SSS, SAS, ASA. There are 5 proofs tobe completed.
Worksheet
Curated OER

Congruent Triangles Homework

For Students 9th - 10th
In this geometry worksheet, students use proofs to solve properties of triangles. They differentiate between congruent and similar triangles. There are 15 questions.
Worksheet
Curated OER

The Premises of Geometry

For Students 9th - 10th
In this geometry worksheet, students solve for missing midpoints, segments and angles using algebraic equations. They use geometric properties to solve these equations. There are 32 questions on 7 different worksheets.
Worksheet
Curated OER

Circle Proofs

For Students 10th
For this circle proofs worksheet, 10th graders complete 4 different problems that include circle proofs. They respond to each of the questions that deal with circle proofs. Then, students read the given information and use the circle...
Assessment
Inside Mathematics

Rhombuses

For Teachers 9th - 12th Standards
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...
Worksheet
Curated OER

Triangles

For Students 10th
In this geometry worksheet, 10th graders solve problems involving triangular inequality. They apply the proofs and theorem of triangles to solve these problems. There is an overview and one question.
Worksheet
Curated OER

Euclidean Proofs involving Triangles and Circles (Congruency Proofs)

For Students 10th
For this geometry worksheet, 10th graders focus on Euclidean proofs involving triangles and circles.  The eight page worksheet contains eight proofs.  Solutions are not provided. 
Worksheet
Curated OER

Properties of Geometry

For Students 10th
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...