Answer:
87 m²
Explanation:
The picnic area is the white inner rectangle, while the courtyard is the outer pink rectangle.
The area of the courtyard available for use = area of the pink rectangle - area of the white rectangle
✔️Area of the courtyard (pink rectangle) = L*W
L = 13 m
W = 7 m
Area of pink rectangle = 13*7 = 91 m²
✔️Area of the picnic (white rectangle) = L*W
L = 4 m
W = 1 m
Area = 4*1 = 4 m²
✅Area available in the courtyard for use = 91 m² - 4 m² = 87 m²