1. Irrigation Circles

2. Air view of irrigated fields
Center pivot irrigation (sometimes called central pivot irrigation), also called circle irrigation, is a method of crop irrigation in which equipment rotates around a pivot. A circular area centered on the pivot is irrigated, often creating a circular pattern in crops when viewed from above.
Air view of irrigated fields

3. What are some mathematical ideas that relate to this picture?

4. A farmer has a square plot of land measuring 16 square miles
A farmer has a square plot of land measuring 16 square miles. He wants to irrigate his crops in a circular pattern with one system that will be moved around. Any land that is double-watered is considered unusable for farming. The farmer has been irrigating his land as four circular fields for many years. His son thinks it may be more efficient to add a fifth irrigation site at the center of his land as illustrated in the given diagrams.
Which irrigation plan has the least “wasted” farm land?
Using words, numbers, and pictures, explain your group solution(s) on chart paper. Be sure that you write your names on the front of your poster.

5. Take the next three minutes and summarize what you learned or reviewed from today’s lesson. Use appropriate mathematical language in your summary.
Is there anything that was unclear on which you would like further discussion?

6. Reference
accessed September 3, 2009.