West Contra Costa Unified School District
Parallel Lines Cut by a Transversal
Parallel lines seem so right for each other. It's too bad they'll never, ever meet. Learners use tracing paper to discover relationships among angles formed by two parallel lines cut by a transversal. They apply this information to find...
EngageNY
Families of Parallel Lines and the Circumference of the Earth
How do you fit a tape measure around the Earth? No need if you know a little geometry! Pupils begin by extending their understanding of the Side Splitter Theorem to a transversal cut by parallel lines. Once they identify the...
EngageNY
Characteristics of Parallel Lines
Systems of parallel lines have no solution. Pupils work examples to discover that lines with the same slope and different y-intercepts are parallel. The 27th segment of 33 uses this discovery to develop a proof, and the class determines...
Curated OER
Introduction to Parallel Lines in Euclidean Space and in Spherical Space
Eighth graders are introduced to the basic concepts of Geometry and their definitions in Euclidean space. They draw and define the following terms: point, line, and line segment. Students also define the terms colliner and...
Curated OER
Geometry Lesson 7: Line Segments And Angles
Fourth graders examine and identify line segments and angles using dot paper to draw them. They look at vertical, horizontal, intersecting, parallel and perpendicular lines, draw right angles and angles that are greater than and less...
Illustrative Mathematics
The Geometry of Letters
Use the alphabet as a tool for teaching your class about geometric figures. Break apart capital letters into line segments and arcs. Classify angles as right, acute, or obtuse. Identify parallel and perpendicular lines. An excellent...
EngageNY
First Consequences of FTS
Challenge the young mathematicians to find the exact coordinates of a dilated point. The fifth segment in a 16-part series introduces the class to the converse of the Fundamental Theorem of Similarity. Scholars use the theorem to...
Curated OER
Points, Lines, Planes, and Space
For this points, lines, planes, and space worksheet, students solve word problems dealing with points, lines, planes, and space. Students complete 20 individual problems and 20 group problems.
Curated OER
Dividing Line Segments into n Congruent Parts
Students identify lines, and line segments. In this geometry lesson plan, students divide line segments into equal congruent parts. They complete a laboratory activity dealing with lines and segments.
EngageNY
Parallel and Perpendicular Lines
Use what you know about parallel and perpendicular lines to write equations! Learners take an equation of a line and write an equation of a line that is parallel or perpendicular using slope criteria. They then solve problems to...
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history lesson with a geometric twist. Pupils relate a short video about geometric properties to modern-day methods of solving for unknown angles. They discuss parallel line theorems and complete...
Curated OER
Are We Sure They Are Parallel?
Fourth graders explore the definition and properties of parallel lines. This high level lesson has students calculate the slope of the two parallel lines, and draw the lines on a Caretsian coordinate system.
Texas Instruments
Points, Lines, and Planes
Students solve problems dealing with points, lines and planes. In this geometry lesson, students differentiate between parallel lines and planes. They find the intersection of lines and planes.
Curated OER
Line Construction
In this geometry worksheet, students construct perpendicular and parallel lines through a given points using a straightedge and a compass. There are 5 questions with an answer key.
Curated OER
Investigating Segments in a Triangle
Pupils investigate segments in a triangle by constructing a triangle using Cabri Jr. They construct segments within the triangle that lie on the midpoints of the triangle's sides. Learners then compare the slope of base of the triangle...
Curated OER
Proportional Segments Between Parallel Lines
Students identify similar triangles. For this proportional segments lesson, students identify corresponding sides, set up ratios, and find the length of the missing side of a triangle. They use the parallel/proportionality...
Curated OER
Sample Lesson Plan on Lines and Angles
Student complete worksheet using the definitions of lines and angle vocabulary. They define the word and follow a direction given on the worksheet such "construct a line." They complete an online tutorial on how to measure angles using a...
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...
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
Points, Lines, and Distance
Students calculate the distance between two points. In this geometry lesson, students define the meaning of the distance between parallel lines. They find the point of intersection of other lines.
Curated OER
Geometry: Lesson 1: Points, Lines, Segments, Angles
Fourth graders examine the concepts of, draw, and label points, lines, segments, and angles, They draw, label, and identify horizontal, vertical, intersecting, parallel, and perpendicular lines. They complete an associated worksheet that...
Curated OER
What's The Idea?
Sixth graders explore line segments, rays, parallel, perpendicular and intersecting lines. The teacher discusses, with the class, real life items that represent each geometric idea studied. They use cotton balls, strings and popsicle...
Curated OER
Identify Polygons: Algebra/Geometry Institute
Eighth graders classify geometric figures. In this polygon lesson, 8th graders identify given geometric figures. They compare and contrast different polygons. Students name line segments, identify parallel lines, and...
Texas Instruments
Investigating Segments in a Quadrilateral
Investigate the properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral. In this properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral lesson, high...