Copy of Circumference of Circles (New)
Directions: Drag the green point to appropriate position to measure the diameter of the circle.
Drag the red point P to straighten and find the circumference. Divide the scale of the ruler to measure its length to two decimal places. Use the Zoom In, Zoom Out and Move tools if necessary.
After exploring the tools answer the questions below the circle and ruler tool.
Anthony Or. GeoGebra Institute of Hong Kong.
orchiming@gmail.com
1. Find the Diameter and Circumference.
Drag the green point to appropriate position to measure the diameter of the circle. What is its diameter? Drag the red point P to straighten the circumference. Divide the scale of the ruler to measure its length to two decimal places. Use the Zoom In, Zoom Out and Move tools if necessary. What is the Circumference?
2. A 2 cm diameter
Change the diameter of the circle to 2 cm. What is the Circumference?
3. A 3 cm Diameter
Change the diameter of the circle to 3 cm. What is the Circumference?
4. Dividing Circumference by Diameter
What is circumference ÷ diameter for the 2 cm? What is circumference ÷ diameter for the 3 cm? What do you notice about the answers?