Curated OER
Explaining the equation for a circle
By first starting with an explicit example of a radius and center point, this challenging lesson tries to help students gain an understanding of the Pythagorean theorem and the equation of a circle. Once they have accomplished the first...
Shodor Education Foundation
Pythagorean Theorem
Most adults remember learning about the Pythagorean theorem, but they don't all remember how to use it. The emphasis here is on developing an intuitive understanding of how and when to use the theorem. Young mathematicians explore...
Pennsylvania State University
Pennsylvania State Univ.: Trilingual Packaging Dilemma
This site from the Pennsylvania State University provides a hands-on activity to bridge the gap between right triangles, 30-60-90 and 45-45-90 theorems, and trigonometry, and what every student wants to know, "When will I ever use this?"...