# Browse

## You are looking at 1 - 10 of 823 items for :

• Geometry
• Math Topic
• Refine by Access: All content
Clear All
Restricted access

## The Beauty of Regular Hexagons

Restricted access

## Broken Ceiling Lights: Circular Area Without the Radius

A customer walks in to a lighting store with a broken ceiling light, and the solution to finding a replacement glass illuminates an alternative approach to finding the circumference and area of a circle without knowing the circle’s center, radius, or diameter.

Restricted access

## Problems to Ponder

Problems to Ponder provides 28 varying, classroom-ready mathematics problems that collectively span PK–12, arranged in the order of the grade level. Answers to the problems are available online. Individuals are encouraged to submit a problem or a collection of problems directly to mtlt@nctm.org. If published, the authors of problems will be acknowledged.

Restricted access

Restricted access

## Construct It! Progressively Precise: Three Levels of Geometric Constructions

This article shares an activity scaffolding the construction of the circumcenter of a triangle, culminating with a Triangle-Ball Championship game.

Restricted access

## Construct It! Triangle Puzzle Challenges

This article presents an original puzzle that supports students’ development of visual thinking and geometry ideas based on the Van Hiele levels of geometric thought.

Restricted access

## GPS: Building Popcorn Boxes

Growing Problem Solvers provides four original, related, classroom-ready mathematical tasks, one for each grade band. Together, these tasks illustrate the trajectory of learners’ growth as problem solvers across their years of school mathematics.

Restricted access

When given the opportunity to play with mathematical materials and ideas, children demonstrate their mathematical understanding in innovative ways.

Restricted access

## Model It! Building and Sustaining Cultural Traditions with Ethnomodeling

This geometric transformation-focused ethnomodeling respects individual and collective community experiences and moves toward educational experiences that acknowledge and celebrate the multidimensional aspects related to identity.

Restricted access

## The Do Nothing Machine

The Trammel of Archimedes traces an ellipse as the machine’s lever is rotated. Specific measurements of the machine are used to compare the machine’s actions on GeoGebra with the graph of the ellipse and an ellipse formed by the string method.