Education Development Center
Finding Parallelogram Vertices
Four is the perfect number—if you're talking about parallelograms. Scholars determine a possible fourth vertex of a parallelogram in the coordinate plane given the coordinates of three vertices. They read a conversation...
Illustrative Mathematics
What is a Trapezoid? (Part 2)
This collaborative activity investigates the meaning of a trapezoid and a parallelogram. It begins by presenting two different definitions of a trapezoid. Learners are to reason abstractly the difference between the two definitions and...
Education Development Center
Proof with Parallelogram Vertices
Geometric figures are perfect to use for proofs. Scholars prove conjectures about whether given points lie on a triangle and about midpoints. They use a provided dialogue among fictional students to frame their responses.
Illustrative Mathematics
A Midpoint Miracle
Young geometers develop one of the fundamental properties of quadrilaterals (connecting side midpoints gives a parallelogram) in this short but thought-provoking exercise. Using a combination of hands-on techniques and abstract algebraic...
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...
K-5 Math Teaching Resources
Tangram Cutout
Challenge the spatial thinking of your young mathematicians with this printable tangram puzzle. Using different sized triangles, squares, and parallelograms, children must figure out how to fit all the shapes together to create a square.
Illustrative Mathematics
What Shape Am I?
Sharpen your pencil and grab a ruler, it's time to draw some quadrilaterals! Given the definition of a parallelogram, rectangle, and rhombus, learners draw examples and nonexamples of each figure. The three definitions are...
Curated OER
Symmetries of a Quadrilateral I
Learners examine the properties of quadrilaterals from the point of view of rigid motion. Different types of quadrilaterals are characterized by their symmetries, so learners explore the symmetries of a described quadrilateral to...
Texas Instruments
Texas Instruments: Properties of Parallelograms
This activity shows the student how to construct a parallelogram using Cabri Geometry. Questions are asked after the construction.
Texas Instruments
Texas Instruments: Properties of Parallelograms
In this activity, students go through the process of proving a quadrilateral to be a parallelogram. They understand the various characteristics of a parallelogram.
Texas Instruments
Texas Instruments: Discovering Properties of Parallelograms, Kites & Trapazoids
This activity allows the teacher to cover the properties of a parallelogram, rectangle, rhombus, square, kite, and trapezoid in two days (90 min. block scheduling) Using a group setting students discover these properties using the Cabri...
Texas Instruments
Texas Instruments: Properties of Parallelograms
In this activity, you will construct the geometric object by following the instructions below, and then answer the questions about the object.
Maths Challenge
Maths challenge.net: Parallelogram Property
A "three star geometry problem" requiring knowledge of how to complete geometric proofs properties of parallelogram.
Texas Instruments
Texas Instruments: Special Parallelograms
In this activity, students will study special types of parallelograms like rhombus and rectangle, and investigate properties related to their diagonals.