Curated OER
Triangle Similarity
In this triangle similarity worksheet, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles shown are...
EngageNY
How Do Dilations Map Angles?
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure.
Curated OER
Reflections and Equilateral Triangles
Your learners collaboratively find the lines of symmetry in an equilateral triangle using rigid transformations and symmetry. Through congruence proofs they show that they understand congruence in terms of rigid motions as they prove...
EngageNY
Solve for Unknown Angles—Transversals
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...
Illustrative Mathematics
Points equidistant from two points in the plane
Young geometers apply their deductive reasoning skills and knowledge of proving triangles congruent in a task that asks them to prove if a point lies on the perpendicular bisector of a segment, then it is equidistant from the endpoints...
EngageNY
The Angle-Angle (AA) Criterion for Two Triangles to Be Similar
What do you need to prove triangles are similar? Learners answer this question through a construction exploration. Once they establish the criteria, they use the congruence and proportionality properties of similar objects to find...
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...
Curated OER
Measuring Angles
In this measuring angles worksheet, 10th graders solve and complete 8 various types of problems. First, they use a protractor to find the measure of each angle shown. Then, students find the missing angle measures. They also refer to the...
Curated OER
Similar Polygons Multiple Choice
In this geometry worksheet, students differentiate between similarity and congruence. They find the correct answer using the theorems of similarity and congruence. There are 5 questions with an answer key.
Curated OER
Proofs with Triangles
In this geometry worksheet, students prove triangle congruence by making statements with reasons and concluding with the AAS or HL theorem. There are 2 proofs.
Illustrative Mathematics
Reflections and Isosceles Triangles
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...
Curated OER
Regents Exam Questions GG 10: Solids
In this solids worksheet, students identify true statements that match a given solid. They identify parallel lines. This two-page worksheet contains four problems. Answers are listed on the last page.
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
Proving Lines Parallel Multiple Choice
In this geometry worksheet, learners identify parallel lines, examine and interpret diagrams, and find the value of corresponding angles and lines. This one-page worksheet contains 6 multiple-choice problems. Answers are provided on...
CCSS Math Activities
Smarter Balanced Sample Items: 8th Grade Math – Claim 3
Communication is the key. A dozen sample items require scholars to communicate their reasoning involved in arriving at a solution. The PowerPoint from the Gr. 8 Claim 2 - 4 Item Slide Shows series uses a variety of content to illicit...
Concord Consortium
Mirror, Mirror I
How do you see yourself? Young mathematicians consider whether it's possible to view their whole bodies in a mirror with a length that is half their height. They write a letter to a friend explaining their positions mathematically.
Virginia Department of Education
Inductive and Deductive Reasoning
Introduce pupils to the two types of reasoning, inductive and deductive. Classmates work in pairs or small groups to learn the difference between the two and apply these reasonings to develop valid conclusions.
Curated OER
Inverse and Converse
In this geometry instructional activity, students identify given statements for the inverse, converse and contra-positive of a conditional statement. There are 9 questions with an answer key.
Curated OER
Grade 5: Testing for Tessellations
Fifth graders use formal geometric language to describe polygons (and other shapes) that will tessellate the plane and those that will not. Students make generalizations about the characteristics of a polygon (or other shape) that will...
Curated OER
Challenge: Skills and Applications Lesson 1.3
In this skills worksheet, students explain the Segment Addition Postulate, provide examples and counter examples and determine congruent line segments. This one-page worksheet contains 11 multi-step problems.
Curated OER
Nested Similar Triangles
Nested triangles have been created so that they share a common vertex and vertex angle. Learners drag the endpoints of the side that is opposite the common angle to discover the conditions that make the nested triangles similar. When...
Curated OER
Points, Lines and Planes
For this points, lines and planes worksheet, 10th graders solve and complete 9 various types of problems. First, they name the planes that intersect a figure shown. Then, students determine the points that are collinear and coplanar in...
Curated OER
Proofs with Triangles Self-check Practice
In this triangle theorems worksheet, students identify the theorem used to prove the specified triangular relationship. Students are shown an illustration of two or more triangles. They identify the postulate that would be used to prove...
Illustrative Mathematics
Are They Similar?
Learners separate things that just appear similar from those that are actually similar. A diagram of triangles is given, and then a variety of geometric characteristics changed and the similarity of the triangles analyzed. Because the...