ClassFlow
Class Flow: Goats and Monsters
[Free Registration/Login Required] Students explore methods to measure lengths of squares and radius of a circle in trying to keep a goat from escaping.
Houghton Mifflin Harcourt
Houghton Mifflin Harcourt: Saxon Activity Center: Graphing Calculator Activity: The Coordinate Plane [Pdf]
A graphing calculator lesson on coordinate planes. Detailed examples, demonstrations with key functions, and practice problems included. Acrobat Reader required.
Rice University
Rice University: Cynthia Lanius: Hidden Polygon Activity
On this site students are instructed to locate different types of polygons on triangle grid paper. This page can be printed so that students can actually draw them. It also gives a definitions link for each polygon.
Calculator Soup
Calculator Soup: Rectangle Calculator
Use this calculator if you know 2 values for the rectangle, including 1 side length, along with area, perimeter, or diagonals and you can calculate the other 3 rectangle variables. A square calculator is a special case of the rectangle...
Calculator Soup
Calculator Soup: Parallelogram Calculator
Calculate certain variables of a parallelogram depending on the inputs provided. Calculations include side lengths, corner angles, diagonals, height, perimeter, and area of parallelograms.
Jim Loy
Jl's Math Page: The Golden Rectangle and the Golden Ratio
This is a personal site from Jim Loy that describes the golden rectangle and the golden ratio. Includes several diagrams and pictures as well as formulas. A good background in math is helpful.
Curated OER
Ic Teachers: Shapes Quadrilaterals
Are you looking for a very basic website that will explain the basic properties of a quadrilateral? Use this site to learn about the properties of a square, rhombus, rectangle, parallelogram, trapezoid, and kite. There are also some...
Curated OER
Rectangle
MathWorld provides the definition of a rectangle and the area formula of a rectangle.