Answer:
151 m² (to the nearest m²)
Step-by-step explanation:
Find the areas of the two circles and then subtract the smaller area from the larger; the difference represents the area of the sidewalk.
Area of larger circle: A = π(13 m)²
Area of smaller circle: A = π(11 m)²
Exact area of sidewalk: π(13² - 11²) m²
The approx. area of the sidewalk is obtained by subbing 3.14 for π in the above expression:
Approx. sidewalk area = 3.14(169 - 121) m² = 151 m²