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....
Mathematics Vision Project
Module 3: Geometric Figures
It's just not enough to know that something is true. Part of a MVP Geometry unit teaches young mathematicians how to write flow proofs and two-column proofs for conjectures involving lines, angles, and triangles.
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...
CK-12 Foundation
Parallelogram Proofs: Quadrilaterals that are Parallelograms
What conditions must be met for a quadrilateral to be a parallelogram? A slider interactive allows individuals to move the vertices of a quadrilateral. They answer questions that prove whether a given quadrilateral is a parallelogram.
Curated OER
Using Proof in Algebra
In this using proofs in algebra activity, 10th graders solve 2 proofs by applying the many rules from algebra for the Properties of Equality for real numbers. They name the property that justifies each statement as seen in the...
Curated OER
Proofs: Solving Equations
In this proofs worksheet, high schoolers solve 4 short answer problems. Students identify the correct reason for each step in solving each multi-step equation.
Curated OER
Getting It Right! An Investigation of the Pythagorean Theorem
Learners construct a variety of right triangles using a right-angled set square, cutting corners from pieces of paper or cardboard, and using dynamic geometry software. They measure the sides of these various right triangles and record...
Flipped Math
Side Splitter Theorem
Apply perspective to similarity. Individuals learn about the Side Splitter Theorem by looking at perspective drawings. Pupils use the theorem and its corollary to find missing lengths in figures. Next, they practice using the theorem and...
EngageNY
Congruence Criteria for Triangles—ASA and SSS
How do you know if a pair of triangles are congruent? Use the lesson to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through transformations and...
EngageNY
Special Lines in Triangles (part 2)
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
EngageNY
Congruence Criteria for Triangles—SAS
Looking for a different approach to triangle congruence criteria? Employ transformations to determine congruent triangles. Learners list the transformations required to map one triangle to the next. They learn to identify congruence if...
EngageNY
Looking More Carefully at Parallel Lines
Can you prove it? Making assumptions in geometry is commonplace. This resource requires mathematicians to prove the parallel line postulate through constructions. Learners construct parallel lines with a 180-degree rotation and then...
EngageNY
Review of the Assumptions (part 2)
Is the amount of information getting overwhelming for your geometry classes? Use this strategy as a way to organize information. The resource provides a handout of information studied in relation to triangle congruence. It includes a...
Curated OER
Geometry, Measurement & Reasoning
Students construct two-column proofs. In this geometry instructional activity, students use deductive reasoning and geometric properties to justify given geometric statements. Students compare and contrast proofs.
Curated OER
Paragraph Proofs
Students explore the concept of paragraph proofs. For 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...
Curated OER
Indirect Euclidean Proofs
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...
Curated OER
Indirect Euclidean Proofs
In this indirect Euclidean proof worksheet, students write statements supporting the reasons for a given proof. This one-page worksheet contains ten problems.
Curated OER
Quiz: Beginning Congruent Triangle Proofs
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.
Curated OER
The Truth About Triangles And Proofs
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...
EngageNY
Solve for Unknown Angles—Angles and Lines at a Point
How do you solve for an unknown angle? In this sixth installment of a 36-part series, young mathematicians use concepts learned in middle school geometry to set up and solve linear equations to find angle measures.
EngageNY
Proving the Area of a Disk
Using a similar process from the first lesson in the series of finding area approximations, a measurement resource develops the proof of the area of a circle. The problem set contains a derivation of the proof of the circumference formula.
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.
Flipped Math
Reasoning and Proof
Make sure the conditions are right. Pupils watch a video introducing conditional statements and their related statements. Learners find out how to identify the hypothesis and conclusion as well as write the converse, inverse, and...
Other popular searches
- Geometry Proofs Worksheets
- Coordinate Geometry Proofs
- Basic Geometry Proofs
- Lesson on Geometry Proofs
- Proofs Geometry
- Geometry Proofs Polygon
- Geometry Proofs and Axioms
- Geometry Proofs Squares
- Geometry Proofs Angles
- Geometry Proofs + Square
- Euclidean Geometry Proofs
- Indirect Proofs Geometry