Geometry & Trigonometry 225 listings
OpenStax: Algebra and Trigonometry

Algebra and Trigonometry provides a comprehensive exploration of algebraic principles and meets scope and sequence requirements for a typical introductory algebra and trigonometry course.

Crash Course: Study Hall Algebra #10 - What Does "Graphing an Equation" Mean?
Crash Course

If you’ve had much experience with Algebra and Geometry, you know that graphs are a thing.

Mathalicious: Belly of the Beast

In this lesson, students model the bodies of different sharks using cylinders, and explore how the volume of a cylinder changes when its dimensions change.

youcubed: Kite in a Square
youcubed (Stanford University)

Geometry lovers, give this one a try!

youcubed: Framing Rectangles (6-8)
youcubed (Stanford University)

In this activity students explore the relationship between the area of a rectangle and the number of squares that make up a border around it.

youcubed: Shape Origami (3-5)
youcubed (Stanford University)

In this activity there are many different possible solutions, which gives students opportunity to be creative, and to discuss their sense making.

Real World Math: Concept Lessons - Oil Spill Estimates
Real World Math

Unfortunately, real world math lessons are sometimes learned from tragedy. 

Illuminations: Learning to Measure with Ladybug
Illuminations (National Council of Teachers of Mathematics)

The mathematical foci of this lesson are geometric concepts, location, navigation, direction, and spatial relationships and measurement concepts, using nonstandard units to measure a distance, and the iteration of units, measurement by using the same unit of measure repeatedly to determine the total.

Illuminations: Parking at the Mall
Illuminations (National Council of Teachers of Mathematics)

Students participate in an activity in which they develop number sense in and around the shopping mall.

Illuminations: Gallery Walk
Illuminations (National Council of Teachers of Mathematics)

This lesson is designed to allow students to view the work of other students in the class and to explain their own work.

Illuminations: Finding the Area of Trapezoids
Illuminations (National Council of Teachers of Mathematics)

Students discover the area formula for trapezoids, as well as explore alternative methods for calculating the area of a trapezoid.

NRICH: Tangram Pictures
NRICH (University of Cambridge)

Use the tangram pieces to make our pictures, or to design some of your own!

K-12 Category Menu

What are you looking for?