# Circumference and Diameter

Topic:
Geometry
The purpose of this app is to examine the relationship between the diameter and circumference of a circle.
• The diameter slider changes the diameter of the circle
• "Roll the Circle" will unroll the circumference of the circle into a segment as it is slid to the right.
• Once unrolled, use the checkbox to see the full segment of the circumference, the length of the diameter, and the measure of the circumference.
1. Use diameter = 1.5. How many diameters are created when the circumference is unrolled?
2. Use diameter = 2. How many diameters are created when the circumference is unrolled?
3. Use diameter = 4. How many diameters are created when the circumference is unrolled?
4. Try your own diameter measure. How many diameters are created when the circumference is unrolled?
5. Examine your 4 responses. What relationship would you say exists between the measurements of the diameter and circumference of a circle?
6. Google the circumference of a circle. How does this relate to what you determined in this app?