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...
Illustrative Mathematics
Lines of Symmetry for Quadrilaterals
Explore how lines of symmetry help define different categories of quadrilaterals. Looking at a square, rectangle, trapezoid, and parallelogram, young mathematicians discover that each shape has its own, unique symmetry. Encourage your...
Illustrative Mathematics
What is a Trapezoid? (Part 1)
Challenge your class to construct a definition for trapezoids. Looking at four examples and four non-examples, students individually create definitions and use them to classify an unknown shape. Allow for small group and whole-class...
Illustrative Mathematics
All vs. Only Some
All shapes have certain defining attributes that set them apart from others. In order to understand this, young mathematicians look at examples and non-examples of triangles, rectangles, and squares, working as a whole class to create...
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...
Exploratorium
The Four-Square Quilt
Youngsters recognize that triangles can be combined together to make various shapes. The learning activity provides a series of seven steps that engage children in applying transformations to triangles. Pupils use a quilt template and...
Curated OER
Shapes and Their Insides
Learners follow a series of instructions for drawing and coloring different shapes in order to learn the difference between the perimeter and area of a polygon. Then they are asked to find the perimeter and area of a 3x4 rectangular...
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...
Illustrative Mathematics
Grandfather Tang's Story
It's amazing the complex figures that can be made using only a few simple shapes. Following a class reading of the children's book Grandfather Tang's Story by Ann Tompert, young mathematicians use sets of tangrams to create models...
Illustrative Mathematics
Alike or Different Game
How are a circle and triangle alike? How are they different? These are the types of questions children will answer while playing this fun geometry game. Including a variety of conventional and unconventional shapes, this activity allows...
Illustrative Mathematics
Overlapping Rectangle
Challenge young mathematicians' ability to compose and decompose shapes with this fun geometry puzzle. The goal is simple, locate all of the rectangles shown in a picture of three overlapping rectangles. Perform this activity as a whole...
Curated OER
Symmetries of a Quadrilateral II
Learners investigate the symmetries of a convex quadrilateral in a collaborative activity. Rigid motion and complements are explored as learners analyze different cases of reflections across a line.
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...
Noyce Foundation
Lyle's Triangles
Try five problems on triangles. Levels A and B focus on shapes that can be created from right triangles. Level C touches upon the relationship between the area of a six-pointed star and the area of each triangle of which it is composed....
Illustrative Mathematics
Counting Squares
Challenge young mathematicians' understanding of squares with this geometry puzzle. The task is simple, identify as many squares as possible in a 3x3 array. Allow learners to work independently or in pairs as they search for squares,...
Curated OER
Task: Grain Storage
Farming is full of mathematics, and it provides numerous real-world examples for young mathematicians to study. Here, we look at a cylinder-shaped storage silo that has one flat side. Given certain dimensions, students need to determine...
Curated OER
Tile Patterns I: Octagons and Squares
This can be used as a critical thinking exercise in congruence or as a teaching tool when first introducing the concept. Four octagons are arranged in such a way that a square is formed in the middle. With this information, geometry...
Other
Gvsu: Quadrilateral Hunt
The learning activity asks students to identify quadrilaterals by characteristics rather than appearance. Learners drag the vertices of the shape to reveal the true shape of the quadrilateral. [Requires Java.]
Texas Instruments
Texas Instruments: Investigating Segments in a Quadrilateral
In this activity, students use the tools of Cabri Jr to test their knowledge of geometry. They investigate the properties of the shape formed by connecting the midpoints of adjacent sides of a quadrilateral.
Texas Instruments
Texas Instruments: Classifying Quadrilaterals
Students will be sent ordered pairs through lists using the TI-Navigator. These pairs will then be graphed as a line graph and students will classify the shape of the quadrilateral and justify their choice.
Illustrative Mathematics
Illustrative Mathematics: 4.g What Shape Am I?
In this task, students ultimately use the definitions they are given for three types of quadrilaterals and what they know about parallel sides to identify that a square fits all the definitions and explain why. Aligns with 4.G.A.2.
NumberNut
Number Nut: Shapes, Symbols, and Colors: 2 D Shapes
Did you know that two-dimensional shapes are also called polygons? This lesson describes the various 2-D shapes and includes two interactive games to reinforce skills.
National Council of Teachers of Mathematics
Nctm: Illuminations: Cutting Corners
Students will use their knowledge of plane figure attributes to create and view shapes by cutting and rotating shapes to stimulate discussions on names and attributes of various shapes they do not regularly encounter.
Ministerio de Educacion, Cultura y Deporte (Spain)
Cnice: Relacion De Ejercicios Interactivos.
In Spanish. Interactive activities online on various geometric and trigonometric concepts such as area, perimeter, secants, tangents, etc. A terrific resource for students. Site is organized acoording to shape. (triangle, quadrilaterals,...