Curated OER
Circle Picture
This site provides definitions for different parts of a circle, pictures to more clearly represent formulas involving circles. Some of the formulas discussed include: area of a circle, area of a sector of a cirles, circumference, length...
Alabama Learning Exchange
Alex: Geometric Quilts
Young scholars will use a square to investigate other polygonal shapes that can be formed. Students will work with these polygons to make designs that will later constitute cooperatively designed quilts. The quilts will be made by...
Purple Math
Purplemath: Geometry Word Problems: Introduction
Introduces how to set up and solve simple geometric-figure word problems. Includes advice regarding formulas to memorize.
Maths Challenge
Maths challenge.net: Annulus
An annulus of a circle is defined and then a proof like problem is posed involving area and radius of circles.
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,...
Maths Challenge
Maths challenge.net: Inscribed Rectangle
This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles to solve this equal area of inscribed polygons problem.
Khan Academy
Khan Academy: Radius and Diameter
Practice problems finding radius and diameter of a circle.
Annenberg Foundation
Annenberg Learner: Math in Daily Life: Home Decorating
This exhibit is designed to show students that geometry really does apply to the real world. By taking viewers through a home decoration project, students learn how to calculate area of a rectangle and circle.
Vernet -Virtual Education Resources Network
Salon Hogar: Referencia Rapida De Formulas Geometricas
This site provides the user with a useful reference to different geometric forms, their elements, formulas, and areas. Entirely in Spanish.
Analyze Math
Analyze Math: Polygons Problems
Here are four problems about the area of a regular polygon. Start by finding the area of a hexagon inscribed in a circle of radius 10, and end by proving that as the number of sides of the polygon increases, the area of the polygon...
Cuemath
Cuemath: Radius
This reference tool explores the radius of a circle. Provides definitions, solved examples, and practice questions with answers.
Cool Math
Coolmath: Precalculus Basic Formulas to Know
This CoolMath resource provides an introduction to some Precalculus formulas.
Other
Allmath: Math Glossary
Are your students having difficulty understanding math terminology? Try this A-Z glossary on math related terms. It's quick, easy to read, and very complete.
Calculator Soup
Calculator Soup: Annulus Calculator
This online calculator will find the area, circumference, and radii of an annulus. With any 2 known variables, you can calculate the other 5 unknowns.
University of St. Andrews (UK)
University of St. Andrews: James Gregory
This site, which is provided for by the University of St. Andrews, contains information on the mathematician Gregory and his accomplishments.
Math2
Math2
This is a site for students and teachers of all grade levels. If you are looking for math tables, general information about math topics, or you would like to ask a question, this is the site to visit.
Mr. Martini's Classroom
Mr. Martini's Classroom: Teacher's Figure Library: Geometric Figures
This interactive resource provides an example picture of the geometric figure chosen by students to review.
Khan Academy
Khan Academy: Circumference and Rotations
Practice these problems with circumference and rotations.
Calculator Soup
Calculator Soup: Volume Calculator
Use this online calculator to calculate the volume of geometric solids including a capsule, cone, frustum, cube, cylinder, hemisphere, pyramid, rectangular prism, sphere, and spherical cap.
National Council of Teachers of Mathematics
The Math Forum: Multicultural Math Fair: Srinivasa's Spheres
Straightforward lesson that introduces learners to pi by letting them measure real objects and solve a challenge problem. Includes instructions and a "Data Sheet" for keeping track of measurements. Available in English and Spanish.