EngageNY
Congruence, Proof, and Constructions
This amazingly extensive unit covers a wealth of geometric ground, ranging from constructions to angle properties, triangle theorems, rigid transformations, and fundamentals of formal proofs. Each of the almost-forty lessons...
eGFI
Lesson: Zero-Energy Home Design
Challenge young engineers to design a one-bedroom scale house to collect and maintain as much heat as possible. Particular constraints must be adhered to, but creativity is also allowed. Included is a diagram and background information...
Curated OER
Proof of the Pythagorean Theorem Using Transformations
Middle and high schoolers construct a triangle using Cabri Jr. They construct squares on each of the legs and hypotenuse of the triangle. Pupils show that the area of the squares on the leg equal the area of the square on the hypotenuse.
Curated OER
Dilations with Matrices
Math whizzes explore dilations. They use matrices to perform dilations centered at the origins of triangles and investigate the effect of scale factor on the size relationship between the pre-image and the image of a polygon. A link to...
Curated OER
Dilations in the Plane
Tenth graders investigate dilations and explore the dilation transformation before investigating the properties of a dilation using Cabri Jr. Students extend the concept of dilatation to the coordinate plane.
Curated OER
All Systems Go!
Secret codes are so much fun, and a great way to practice nearly any math skill. Let your class become code breakers as they investigate inverse matrices. They use TI-Nspire technology to solve systems of equations which help them crack...
Radford University
Parallel Lines Cut By a Transversal
Perhaps planning a city isn't so difficult after all. Scholars first perform geometric constructions and investigate how parallel lines are useful in real-world situations. They then work on a city design project, drawing street maps,...
Radford University
Building a House
Ever dream of becoming an architect? Here's your chance to give it a try. After reviewing facts about triangles and quadrilaterals, pupils learn about the basics of architecture by talking to an architect or housing expert. They use...
Radford University
Parallel Lines Cut by a Transversal
Use the parallel lines to find your way. After first reviewing geometric constructions and the relationships between angles formed by parallel lines and a transversal, young mathematicians write proofs for theorems relating to parallel...
Radford University
Quadrilaterals
Connect the quadrilaterals. Working in teams, pupils use a variety of tasks to make connections between special quadrilaterals. With the properties well defined, the groups construct quadrilaterals based on those properties. Learners...
Mathed Up!
Loci and Constructions
A General Certificate of Secondary Education math review has class members make basic constructions. Using a protractor and a ruler along with a compass, pupils develop drawings of triangles with given measurements. Scholars use their...
Corbett Maths
Construct a 45 Degree Angle
Create a 45-degree angle without bisecting an angle. A video shows a method to construct a 45-degree angle without needing to bisect a right angle. By constructing an isosceles right triangle, the presenter constructs a 45-degree angle...
Corbett Maths
Construct a 30 Degree Angle
Split it down the middle. Using the tools of geometric construction, the video shows two different methods of constructing a 30-degree angle. The first method bisects an angle of an equilateral triangle. The second uses the diagonal of a...
Corbett Maths
Angle Bisector
Cut it in half with a compass and straightedge! Using construction tools, a video shows how to create an angle bisector. The presenter points out what it means to bisect an angle in terms of the measure and distances from the sides of...
Corbett Maths
Perpendicular from a Line to a Point
Take steps in the right direction. With a short demonstration, a video shows the steps to construct a perpendicular from a line to a point. Using a protractor, the narrator confirms the resulting construction is perpendicular, and then...
Corbett Maths
Perpendicular Through a Point on a Line
Use one construction to complete a second. The short video shows how to incorporate the steps of a perpendicular bisector to create a perpendicular to a point on a line. With their own straightedges and compasses, classmates then...
Corbett Maths
Perpendicular Bisector
Where should the statue be located? The resource explains how to use a compass and straight-edge to construct the perpendicular bisector of a line segment. Using an exam question, the narrator models how to solve an application problem...
Mathematics Vision Project
Module 2: Congruence, Construction and Proof
Construct yourself a winning geometry unit. A set of lessons introduces geometry scholars to constructions and proofs with compasses and straightedges. It also covers triangle congruence through transformations. This is the second of...
Mathematics Vision Project
Congruence, Construction and Proof
Learn about constructing figures, proofs, and transformations. The seventh unit in a course of nine makes the connections between geometric constructions, congruence, and proofs. Scholars learn to construct special quadrilaterals,...
Noyce Foundation
Circular Reasoning
Examine the origin and application of pi in five different levels. The five lessons in the resource begin with an analysis of the relationship between the radius and circumference of a circle. The following lessons lead learners through...
Noyce Foundation
Once Upon a Time
Examine the relationship between time and geometry. A series of five lessons provides a grade-appropriate problem from elementary through high school. Each problem asks learners to compare the movement of the hands on a clock to an angle...
Noyce Foundation
Poly-Gone
Investigate polygons from rectangles to triangles to octagons. Each level of the five-problem series targets a different grade level. Beginning with the level A problem, learners examine the relationship between area and perimeter by...
Noyce Foundation
What's Your Angle?
Math can be a work of art! Reach your artistic pupils as they explore angle measures. A creative set of five problems of varying levels has young learners study interior and exterior angle measures of polygons. The introductory levels...
Virginia Department of Education
Constructions
Pupils learn the steps for basic constructions using a straightedge, a compass, and a pencil. Pairs develop the skills to copy a segment and an angle, bisect a segment and an angle, and construct parallel and perpendicular lines.