Curated OER
Perpendicular Lines
Students differentiate between parallel and perpendicular lines. In this geometry lesson, students identify the different angles created by perpendicular lines and parallel lines. They name the angles that are form when parallel lines...
Curated OER
Identifying Parallel and Perpendicular Lines
Students explore basic geometry. In this geometry activity, students study points and lines that exist in flat planes. Students investigate parallel and perpendicular lines.
Curated OER
Sail Problem
High schoolers explore the proportional relationships involved in multiple parallel lines being cut by a transverse line. They complete a sail design problem, that involves finding the lengths of pieces of fabric along the edge of a sail...
Curated OER
Angle Relationships
Tenth graders explore the angle relationships that exist when two lines intersect. In this geometry lesson, 10th graders estimate the measure of given angles and use their graphing calculator tools. Students use this knowledge to find...
Curated OER
Parallel and Perpendicular Line Construction
In this geometry worksheet, students construct parallel and perpendicular lines given a straight edge and a compass. Their lines pass through a given point. There are 4 questions with an answer key.
Curated OER
Parallel-o-Home
Students investigate the usage of parallel and perpendicular shapes in the real world. For this geometry lesson, students investigate shapes for properties that are related to the real world. They relate all the properties of shape tot...
Curated OER
Triangle's Interior Angles
Given a pair of parallel lines and a triangle in between, geometers prove that the sum of the interior angles is 180 degrees. This quick quest can be used as a pop quiz or exit ticket for your geometry class.
Illustrative Mathematics
What is a Trapezoid? (Part 1)
Challenge your class to construct a definition for trapezoids. Looking at four examples and four non-examples, students individually create definitions and use them to classify an unknown shape. Allow for small group and whole-class...
EngageNY
Fundamental Theorem of Similarity (FTS)
How do dilated line segments relate? Lead the class in an activity to determine the relationship between line segments and their dilated images. In the fourth section in a unit of 16, pupils discover the dilated line...
Curated OER
Geometry Practice GG10: Prisms
In this prisms worksheet, students identify the number of faces in a prism. They locate the parallel edges. Students determine the names of prisms. This two-page worksheet contains 3 problems. Answers are...
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
Mid-Module Assessment Task - Geometry (Module 1)
How do you prepare class members for the analytical thinking they will need in the real world? An assessment requires the higher order thinking they need to be successful. The module focuses on the concept of rigid transformations...
EngageNY
Criterion for Perpendicularity
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...
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.
Illustrative Mathematics
Equal Area Triangles on the Same Base II
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,...
Curated OER
Transformations and Matrices
There are four activities in this extensive lesson covering the identity matrix and scaling, the linear representation of translations, the linear representation of rotations, and reflections. In small groups, they use the Cabri II...
Curated OER
Properties of Lines - Parallel and Perpendicular
Sixth graders identify parallel and perpendicular lines in the alphabet. In this line properties lesson, 6th graders use the letters of the alphabet to show parallel and perpendicular lines. Students open a Geogrid Mat on the computer...
Curated OER
Angles and Transversals
Pupils explore the concept of angles and transversals. They construct parallel and non-parallel lines cut by a transversal using Cabri Jr. Learners then determine which angles are congruent and the relationship of angles when two lines...
Curated OER
Geometry and Quilting
Fourth graders combine geometry and language arts skills while examining quilt-making. After identifying the geometric shapes contained in quilts, they write stories to encompass the quilt border. Students conclude by creating and...
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...
EngageNY
Rotations of 180 Degrees
What happens when rotating an image 180 degrees? The sixth lesson in the series of 18 takes a look at this question. Learners discover the pattern associated with 180-degree rotations. They then use transparency paper to perform the...
Curated OER
Tennis Balls in a Can
Make your classroom interesting by teaching or assessing through tasks. Deepen the understanding of Geometry and motivate young mathematicians. The task uses investigation with tennis balls and their container to prompt learners to...
Curated OER
Pyramid Activity
Pupils explore the concept of pyramids. They determine if two sides of a pyramid are perpendicular using a graphing calculator, then discuss parallel and perpendicular lines and how to determine if two lines are parallel or...
Curated OER
Contructions and Conjectures
Students make constructions and conjectures. For this geometry lesson, students construct right, acute and obtuse angles using a straight edge and a protractor. They investigate parallel lines and the angles formed by the angles.