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.
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 lesson, 10th graders investigate the relationships associated with parallel lines and transversals, perpendicular lines, and the angles formed by these lines. ...
Curated OER
Determining Angle Measure with Parallel Lines
Young scholars 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
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
Making Parallel Lines
Students differentiate between parallel and perpendicular lines. In this geometry lesson, students make conjectures and apply it to solve real life situations. They collect data and make predictions based on the data.
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
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 instructional activity, young geometers investigate and make conjectures about diagonals, angles, and parallel lines of parallelograms.
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.
Curated OER
Parallel-o-Home
Learners 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
Parallel Lines and Properties of Slope
Students define functions to be graphed using the Y=key. They demonstrate how to set up a standard viewing screen using Zoom 6. They discuss and explore mathematical questions on a worksheet.
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...
Curated OER
Properties of Special Quadrilaterals
Teach your mathematicians how to identify the properties of quadrilaterals. In this geometry lesson, students solve for missing angles and sides of a special quadrilateral. They use the TI to move the sides around and create different...
Illustrative Mathematics
Right Triangles Inscribed in Circles II
So many times the characteristics of triangles are presented as a vocabulary-type of lesson, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
Curated OER
Properties of Special Parallelograms
Students identify properties of trapezoids. In this geometry lesson, students are put into groups and use computer programs to analyze polygons. They drag and move the shapes around as they make predictions.
Curated OER
Transversal and Angles
Tenth graders identify angles formed by parallel lines and a transversal. Using meter sticks and bolts, they perform hands-on activities to demonstrate the properties of parallel lines and congruent angles. They color code diagrams to...
Curated OER
Applications of Properties of Quadrilaterals in the Coordinate Plane
Learners explore the concept of quadrilaterals. In this quadrilaterals lesson plan, students use the slope formula, midpoint formula, and distance formula to justify that a given quadrilateral is a parallelogram.