Circular Circles!

In our class, we are studying geometry, and

we are learning about circles.
 

Mrs. Yollis' necklace was made of CIRCLES.

The playground had many CIRCLES. 

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CIRCLE VOCABULARY 

We  learned that circles have a center point. It is the same distance from anywhere on the circle.  

In addition, we  learned that a line segment drawn from the center point to the outside edge of the circle is a radius.


The diameter is a line segment. It passes through the center and has endpoints on the circle.

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After the vocabulary lesson, Mrs. Yollis' students were ready to make their own CIRCLES.

Chalk was tied to a piece of yarn. The yarn was the RADIUS. 
A student sat in the CENTER. 

Keeping the RADIUS tight,

the chalk was dragged around the CENTER creating a CIRCLE!.

 

It was hard to keep the chalk the same distance from the CENTER. 

Finally, we had a beautiful CIRCLE.  

Screech, our local hawk, was too busy hunting to be interested in circles.

 

After the class circle was drawn, 

students broke into teams to create their own CIRCLEs.

 

  

One group used the CENTER from the class CIRCLE.

Now there were two CONCENTRIC CIRCLES!

 

 

 

After the CIRCLES were made, it was time to measure the RADIUS and DIAMETER.

The DIAMETER of this CIRCLE was 6 feet.

We divided the DIAMETER in half and got a  RADIUS of 3 feet.

 

Here we used a benchmark unit of 1 yard to predict the DIAMETER. 

Some students marked off their guess using giant steps. 

Each team's circle had a different radius, and of course, a different diameter!

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Some students confuse a circle and a sphere.

A circle is 2-dimensional.

A sphere is 3-dimensional.

Here is a quiz. Do you know the difference?

Circle or Sphere? on PhotoPeach

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How do you like our circles? 

What circles can you find around your house?

Try measuring the radius of a circle you find at home and let us know what the measurement was.

Remember, to find the diameter, double the radius!