This activity is intended to supplement Geometry, Chapter 11, Lesson 2.
Problem 1 – Nets
Start the Cabri Jr. application by pressing the APPS key and selecting CabriJr. Open the file CYLINDER by pressing Y=, selecting Open..., and selecting the file. You should see a partial net of a right cylinder.
1. What changes occur to the net when the point H is dragged?
2. What changes occur to the net when the point R is dragged?
3. Record 2 sets of measurements of the net:
4. What is the result when you divide the Rectangle Length by the Circle Radius?
5. Explain this result. Drag point R to confirm your conjecture.
Problem 2 – Surface Area
6. Record these measurements:
Circle Radius: __________
Circle Area: __________
Rectangle L: __________
Rectangle Area: __________
Rectangle H: __________
7. Record the steps you performed to find the surface area of the cylinder:
8. What is the surface area of your cylinder?
9. How is the method used in #7 above related to the formula SA=2πR2+2πRH?