Hi, this is the notation for inclusion of all real
numbers.

We can also state numbers which are positive or negative with a sign on top of the R notation like so:
In a football game a team might move up 20 yards but they might get a penalty for something and push them back 15 yards.
Hope this helps. I'm just in a rush.
Answer:
o 26.98398684 en forma decimal
Step-by-step explanation:
Answer:
615.75
Step-by-step explanation:
you divide 87.92 by pi (3.14 in this case) to get diameter, which you divide by 2 to get the radius to solve for area which you get 615.75