The school gardening club is designing a rectangular flower bed. The length of the bed is 20 \(meters\) and the width is 5 \(meters\).
 
1. What is the area of the flower bed?
 
2. If the club wants to put a fence around the bed. What is the perimeter?
 
3. Is the area of the flower bed rational or irrational number?
 
4. If the club decides to increase the length to  80meters. What will the new area be?