A calf is tied to a rope that is lengthened from 12 meters to 23 meters. What is the increase in the area of grass the calf can graze?

Explanation

The additional grazing area is calculated by finding the difference between the areas of two circles with radii 23 m and 12 m respectively. Using the formula πr², the increase equals π(23² - 12²) = π(529 - 144) = π × 385 ≈ 1120 m².