Curated OER
Parallelism in Our Everyday World: Parallel Lines and Beyond
Students broaden their outlook on geometry in their everyday environment. They explore the properties of parallel lines and parallelograms and discover ways to prove the existence of parallel lines and discuss the concept of parallel lines.
EngageNY
Angles Associated with Parallel Lines
Explore angle relationships created by parallel lines and transversals. The 13th lesson plan of 18 prompts scholars use transparency paper to discover angle relationships related to transversals. Learners find out that these angles pairs...
Mathematics Assessment Project
Classifying Equations of Parallel and Perpendicular Lines
Parallel parking might be difficult, but finding parallel lines is fairly simple. In this lesson, learners first complete an assessment task involving parallel and perpendicular lines in the coordinate plane. Individuals then take part...
Curated OER
Constructing Parallel Lines
Students construct parallel lines using a protractor and a straightedge. In this geometry lesson, students identify the properties of parallel lines. They use Cabri to graph and observe the lines.
Illustrative Mathematics
Joining Two Midpoints of Sides of a Triangle
Without ever using the actual term, this exercise has the learner develop the key properties of the midsegment of a triangle. This task leads the class to discover a proof of similar triangles using the properties of parallel lines cut...
Curated OER
Parallel and Perpendicular Lines
Tenth graders explore parallel and perpendicular lines. In this geometry instructional activity, 10th graders investigate the relationships associated with parallel lines and transversals, perpendicular lines, and the angles formed by...
Curated OER
Determining Angle Measure with Parallel Lines
Students observe and solve examples of corresponding angle postulates, alternate interior angle theorems, and exterior and consecutive angles. They complete the Determining Angle Measure With Parallel Lines worksheet.
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.
EngageNY
Informal Proofs of Properties of Dilations
Challenge the class to prove that the dilation properties always hold. The lesson develops an informal proof of the properties of dilations through a discussion. Two of the proofs are verified with each class member performing the...
Curated OER
Parallel and Perpendicular Lines
Learners study parallel and perpendicular lines. In this parallel and perpendicular instructional activity, pupils explore 2-D shapes and determine if the sides are parallel or perpendicular.
Curated OER
Lines, Lines, Everywhere
Students explore linear equation suing real life scenarios. In this algebra instructional activity, students find the slope and intercept of a line. They create table of values to plot their graph and draw conclusions.
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history activity 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 practice...
Virginia Department of Education
Properties of Quadrilaterals
What type of quadrilateral is that? Discover the difference between the types of quadrilaterals. Small groups investigate types of quadrilaterals using geometry software to find their properties. To keep track of the different...
Curated OER
Ruler and Compass Constructions
Fourth and fifth graders examine how to construct perpendicular lines and to bisect angles using rulers and compasses in this unit of lessons. They design a number of polygons using these methods.
Curated OER
Making Parallel Lines
Students differentiate between parallel and perpendicular lines. In this geometry lesson plan, students make conjectures and apply it to solve real life situations. They collect data and make predictions based on the data.
Curated OER
Similar Situations
Students explore intersecting lines. In this intersecting lines lesson, students investigate shapes consisting of parallel, perpendicular, and similar lines. Students investigate these lines in shapes around them.
Alabama Learning Exchange
Mirror, Mirror on the Wall: Reflections of Light
Why can we see our reflection in a window but not a brick wall? Young physicists learn the Law of Reflection and various light properties that help them answer this and other questions about reflection. Use the PowerPoint to introduce...
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...
EngageNY
Definition of Reflection and Basic Properties
Discover the results of reflecting an image. Learners use transparency paper to manipulate an image using a reflection in this fourth lesson of 18. They finish by reflecting various images across both vertical and horizontal lines.
EngageNY
Special Lines in Triangles (part 1)
Allow your pupils to become the mathematicians! Individuals explore the properties of a midsegment of a triangle through construction and measurement. Once they figure out the properties, learners use them to draw conclusions.
Key Curriculum Press
Properties of Special Parallelograms
Rhombuses, rectangles and squares are have special properties. In this lesson plan, young geometers investigate and make conjectures about diagonals, angles, and parallel lines of parallelograms.
Curated OER
Angles and Parallel Lines
Sixth graders draw parallel and intersecting lines to observe and examine the characteristics of alternate interior angles, vertical angles, corresponding angles, and supplementary angles. Through observation, they discover the...
Curated OER
Investigating the Slopes of Parallel and Perpendicular Lines
High schoolers investigate parallel and perpendicular lines. They use Cabri Jr. to construct and explore the relationships between the slopes of parallel and perpendicular lines. The drawing and measurement tools available with Cabri Jr....
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.