National Council of Teachers of Mathematics
Nctm: Standards for School Mathematics
This standards-based NCTM website offers resources for teachers of mathematics for all grade levels, including interactive math tools, lesson plans, online resources, and the like.
Mathigon
Mathigon: Euclidean Geometry: Euclid's Axioms
This lesson focuses on Euclid's Axioms, simple, intuitive statements, that everyone agrees are true. An axiom(or postulate) is a mathematical statement that is regarded as "self-evident" and accepted without proof. A key part of...
Better Lesson
Better Lesson: Rockin' Rhombuses!
Rhombus, the mathematically correct term for "diamond" is the focus of this interactive lesson.
Alabama Learning Exchange
Alex: Determine Transformation(s)
Students will use graphing calculators(TI-83 Plus) to find transformations of polygons.This lesson plan was created as a result of the Girls Engaged in Math and Science, GEMS Project funded by the Malone Family Foundation.
TED Talks
Ted: Ted Ed: Euclid's Puzzling Parallel Postulate
Euclid, known as the "Father of Geometry," developed several of modern geometry's most enduring theorems--but what can we make of his mysterious fifth postulate, the parallel postulate? Jeff Dekofsky shows us how mathematical minds have...
Cuemath
Cuemath: Segment of a Circle
This lesson expands your knowledge about circles by learning about the segment of a circle, which will include its mathematical definition, area of the segment, types of segments in a circle, theorems based on a segment of a circle, and...