In our class, we are studying geometry, and
today we learned about circles.
Mrs. Yollis' necklace was made of CIRCLES.
The playground had many CIRCLES.
* * * * *
CIRCLE VOCABULARY
Mrs. Yollis' necklace was made of CIRCLES.
The playground had many CIRCLES.
* * * * *
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.
* * * * *
After the vocabulary lesson, Mrs. Yollis' students were ready to make their own CIRCLES.
Chalk was tied to a piece of string. The string was the RADIUS.
Here is one radius with a length of 1 yard. (36 inches)
We also created a radius with a length of 3 yards!
Next, we went outside with our two radii. (Radii is the plural of radius.)
One student sat in the CENTER.
We pulled the radius tight, and students pulled the chalk around the center.
QUESTION: With a radius of 1 yard, what was the diameter?
(Answer given below.)
ANSWER: A circle with a 1 yard radius will have a diameter of 2 yards.
1 yard x 2 = 2 yards
or maybe you prefer it in feet:
3 feet x 2 = 6 feet
The bigger circle was much harder to make!
It had a radius of 3 yards (9 feet).
It was hard to keep the radius pulled in a tight line segment. We had to restart at times.
Keep dragging the chalk around the center point!
Finally, we were were able to complete the circle. It was time to measure the diameter!
ANSWER: The circle with a radius of 3 yards has a diameter of 6 yards.
3 yards X 2 = 6 yards
or maybe you prefer it in feet:
9 feet X 2 = 18 feet
Some students confuse a flat circle with a 3-dimensional sphere.
Take this quiz to see if YOU know the difference!
Circle or Sphere? on PhotoPeach
Were you able to create a perfect circle in class?
Do you have any tips?
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