National Council of Teachers of Mathematics
Nctm: Illuminations: Igd: Area of a Parallelogram
This applet will show you how to divide the parallelogram into pieces, arrange them together to form a rectangle, and then use the formula for the area of a rectangle to find the area of the parallelogram.
OER Commons
Oer Commons: Characteristics of Parallelograms
In this lesson, students learn more about the characteristics of parallelograms by folding paper and measuring the angles in a parallelogram. Students use a ruler and protractor to draw parallelograms with given properties. Then,...
Free Math Help
Free Math Help: Special Parallelograms: Squares, Rectangles, and Rhombuses!
Examines special parallelograms. Students learn about a rectangle, rhombus, and square. Definitions and examples with solutions are included.
Better Lesson
Better Lesson: Finding the Area Review and Assessment
Sixth graders find the area of rectangles, triangles, parallelograms, and trapezoids by using formulas or by composing into rectangles or triangles.
OER Commons
Oer Commons: Diagonals of a Rhombus
In this lesson, learners learn how the diagonals of a rhombus are related. They use interactive sketches to learn about the properties of the angles and diagonals of squares, rectangles, rhombuses, parallelograms, and other...
CK-12 Foundation
Ck 12: Interactive Geometry: 4.7 Theorems About Quadrilaterals
Use quadrilateral properties that are unique to parallelograms to prove that the given shape is a parallelogram.
Texas Education Agency
Texas Gateway: Determining Area of Composite Figures
Given composite figures (combinations of rectangles, squares, parallelograms, trapezoids, triangles, semicircles, and quarter circles), students will be able to determine expressions for the area as well as calculate the area of the figure.
National Council of Teachers of Mathematics
The Math Forum: Geoboard Activities
Math Forum provides a set of links to sites that are related to geoboard activities. There are several great links to lessons using geoboards. The links provide insight into how to use them, including how to perform various measurements...
Mathigon
Mathigon: Geometry: Polygons and Polyhedra: Quadrilaterals
This lesson focuses on quadrilaterals which can fall into multiple categories based on the number of sides and the angles.
Ducksters
Ducksters: Kids Math: Quadrilaterals
Explore four-sided polygons called quadrilaterals on this site.