Respuesta :

Matheng
The area of the sidewalk = total area of fountain and sidewalk - area of fountain
∴ The area of the sidewalk = π (r+w)² - πr²
r = 10 feet  ,  and   w = 5 feet
The area of the sidewalk = π (10+5)² - π*(10)² = 225 π - 100π = 125π ≈ 392.7 ft²