Final answer:
The exact area watered by an irrigation system in a circular field with a 20-ft radius is calculated using the formula A = πr^2, resulting in an area of 1256.64 square feet.
Step-by-step explanation:
To find the exact area watered by the irrigation system in a circular field with a 20-foot radius, we need to use the formula for the area of a circle, which is A = πr^2. Here, 'A' represents area of circle, 'r' represents radius, and 'π' is a mathematical constant approximately equal to 3.14. So, we substitute the value of the radius into the formula, as follows:
A = π(20)^2.
After calculation, the area 'A' comes out to be 1256.64 square feet, which is the area being watered by the irrigation system. It is important to note here that the unit of measurement for area is square feet, which is represent by 'ft^2'. This is to distinguish it from linear measurements, denoted in feet.
Learn more about Area of a Circle