Curated OER
Coordinate Geometry Proofs
In this coordinate geometry worksheet, 10th graders solve and draw 10 different problems related to complete proofs in coordinate geometry. First, they prove that a figure with given points is another figure by using slopes. Then,...
Jesuit High School
Geometry Sample Problems
I'd like to prove that this instructional activity has a lot to offer. Seven problems using triangles and parallelograms practice the traditional method of a two-column proof. After the instructional activity is some practice problems...
Virginia Department of Education
Lines and Angles
Explore angle relationships associated with transversals. Pupils construct parallel lines with a transversal and find the measures of the angles formed. They figure out how the different angles are related before constructing...
Mt. San Antonio Collage
Elementary Geometry
Your class may believe that geometry is a trial, but they don't know how right they are. A thorough math lesson combines the laws of logic with the laws of geometry. As high schoolers review the work of historical mathematicians and the...
EngageNY
Angle Sum of a Triangle
Prove the Angle Sum Theorem of a triangle using parallel line and transversal angle relationships. Pupils create a triangle from parallel lines and transversals. They find angle measures to show that the angles of a triangle must total...
Curated OER
Angle Bisectors
In this angle bisector worksheet, 10th graders solve and complete 23 various types of geometry problems. First, they find the angles listed in the figure shown. Then, students determine the sum of the interior angles of a polygon. They...
Curated OER
Geometry: Properties of Triangles
In this properties of triangles worksheet, students use their knowledge of triangles to find determine angle measurement. They use geometric theorems to prove equal angles. This three-page worksheet contains 15 multi-step geometry...
Illustrative Mathematics
Shortest Line Segment from a Point P to a Line L
One of the hardest skills for many young geometers to grasp is to move beyond just declaring obvious things true, and really returning to fundamental principles for proof. This brief exercise stretches those proving muscles as the class...
Curated OER
SSS, SAS, ASA, and AAS Congruence
Students will determine if triangles are congruent and state the appropriate congruence theorem. In this geometry lesson, students will determine what information is needed to determine if a pair of triangles are congruent using ASA,...
Curated OER
Geometry Lines and Angles
In this lines and angles worksheet, 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 diagram...
EngageNY
Properties of Parallelograms
Everyone knows that opposite sides of a parallelogram are congruent, but can you prove it? Challenge pupils to use triangle congruence to prove properties of quadrilaterals. Learners complete formal two-column proofs before moving on to...
EngageNY
Ptolemy's Theorem
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.
EngageNY
Circles, Chords, Diameters, and Their Relationships
A diameter is the longest chord possible, but that's not the only relationship between chords and diameters! Young geometry pupils construct perpendicular bisectors of chords to develop a conjecture about the relationships between chords...
Curated OER
Geometric Proof and Angles
In this geometry worksheet, 10th graders write two-column and paragraph proofs to prove angle pair relationships. The one page worksheet contains five problems. Answers are not included.
Curated OER
Proofs Chapter 2: Geometry
In this geometry worksheet, students look at given pictures and prove congruent lines and angles. This three-page worksheet contains nine multi-step problems.
Curated OER
Geometric Proofs
In this geometric proofs worksheet, students prove supplementary, complimentary, and congruent angles from given models and information. This four-page worksheet contains six multi-step problems.
Curated OER
Identify Similar Triangles With Proofs
In this similar triangle worksheet, students write a two-column proof to explain why determined triangles are similar. Given some line lengths and angle measurements, students use proofs to identify the ratio of specified angles. This...
Curated OER
Pre-Proof Warm-Ups
In this pre-proofs worksheet, 10th graders solve and complete 10 different problems that include various proofs and their definitions. They use the diagram shown and the given information to write the direct conclusion for each case....
Curated OER
Geometry: Angles
In this angle worksheet, students find the value for a given variable. They use similar figures, alternate interior angles, side angle side, and other geometric theorems and proofs to determine the value of the given variable. This...
Curated OER
Geometric Proofs
In this geometric proof worksheet, students use geometric theorems and rules to prove given statements. They prove that given lines and angles are similar. This five-page worksheet contains ten problems.
Math Worksheets Center
Congruent Triangle Proofs Quiz
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....
Curated OER
Quiz: Direct Euclidean Proofs
In this Euclidean proof worksheet, learners observe models and read given proofs. Students determine conclusions based upon the given information. This one-page worksheet contains ten Euclidean proof problems.
Illustrative Mathematics
Similar Triangles
Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...
Curated OER
Verifying Angle Relationships
In this verifying angle relationships worksheet, 10th graders solve and prove various types of problems related to the verification process of various angle relationships. They complete each of the two proofs shown step-by-step, giving a...