When mathematical errors happen, part of the learning is to figure out how it affects the rest of your calculations. The activity has your mathematicians solving for the area of a circular pipe and taking into consideration any errors...

Learners see application of construction techniques in a short but sophisticated problem. Combining the properties of inscribed triangles with tangent lines and radii makes a nice bridge between units, a way of using...

One of the basic properties of inscribed angles gets a triangle proof treatment in a short but detailed exercise. Leading directions take the learner through identifying characteristics of a circle and how they relate to angles and...

Round and round you'll go! Learners watch as different-sized circles fill with coins. They collect data and then make a prediction about the number of coins that will fit in a large circular rug.

Examine the origin and application of pi in five different levels. The five lessons in the resource begin with an analysis of the relationship between the radius and circumference of a circle. The following lessons lead learners through...

What starts as a basic question of division and remainders quickly turns abstract in this question of related ratios and radii. The class works to surround a central coin with coins of the same and different values, then develops a...

So many times the characteristics of triangles are presented as a vocabulary-type of lesson, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...

A basic set-up leads to a surprisingly complex analysis in this variation on the question of surrounding a central circle with a ring of touching circles. Useful for putting trigonometric functions in a physical context, as well as...

This activity is a follow-on activity to inscribing a square in a circle. The overall problem is more complex. It deals with geometric constructions, properties of triangles, and regular hexagons. The final part of the activity...

Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...

Add a sense of excitement to your math class with this race across the country. Using their knowledge of all things circular, young mathematicians work in pairs answering a series of pi-related word problems as they hop from one city to...

The shortest distance from point A to point B is a straight line—or is it? Young scholars determine the shortest route either along a circular path or through the center of the circle. Learners gain a unique perspective on arc length and...

Keep playing with those old toy cars! Pupils estimate the number of toy cars in an art installation. The only information they receive is a picture showing the toy cars arranged in concentric rings and the diameter of the overall...

Farming is full of mathematics, and it provides numerous real-world examples for young mathematicians to study. Here, we look at a cylinder-shaped storage silo that has one flat side. Given certain dimensions, learners need to determine...

Looking for a fun and creative way to celebrate Pi Day? Then this is the resource for you. From a scavenger hunt and trivia contest to PowerPoint presentations and skills practice worksheets, this collection of materials is a...

Unravel the mystery behind the infamous number pi. Scholars complete a series of activities that explores where pi comes from, its digits and estimation strategies. Pupils should be ready to measure, calculate, and look for patterns to...

Happy Pi Day! This collection of games, experiments, and activities leads participants through an exploration of the many aspects and attributes of that mysterious quantity, pi. Activities range from using statistical...

On your mark, get set, GO! The class sprints toward the conclusions in a race analysis activity. The staggered start of the 400-m foot race is taken apart in detail, and then learners step back and develop some overall race strategy...

Take a shot using a lesson on volume! Young learners watch a video showing a trashcan filling with paper balls. The task is to calculate the number of paper balls that will fit in the can. Pupils use volume calculations to make a...

Life science learners discover the range of peripheral vision. They compare the angles at which they can detect motion, colors, and detailed shapes. 

Twenty-five problems cover various circle activities. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution" button to check each step of your...

This WebMath site will assist with finding the radius, diameter, circumference, and area of a circle.

A complete reference guide to circles including parts, angles, and arcs. It provides definitions and interactive activities that enhance further explanation.

[Free Registration/Login Required] Students use the radius and diameter to determine the area of a circle. Click challenge me to answer practice questions and click learn more to watch a video.