A square courtyard has a side length of 35 m. A circular water fountain is built inside it, taking up an area of 770 m². Find the remaining uncovered area of the courtyard.

The correct option is 455 m².

To find the remaining uncovered area of the courtyard, we need to calculate the total area of the square courtyard and subtract the area taken up by the circular water fountain.

Step 1: Calculate the area of the square courtyard

The area of a square is given by the formula:

$\text{Area of square}={\text{side}}^2$

Given the side length of the courtyard is 35 m:

$\text{Area of square}=35\times 35=1225{\text{m}}^2$

Step 2: Determine the area of the circular water fountain

The area occupied by the circular fountain is directly given as 770 m².

Step 3: Calculate the remaining uncovered area

Subtract the area of the fountain from the total area of the square courtyard:

$\text{Remaining area}=\text{Total area of courtyard}-\text{Area of circular fountain}$

$\text{Remaining area}=1225{\text{m}}^2-770{\text{m}}^2=455{\text{m}}^2$

Thus, the remaining uncovered area of the courtyard is 455 m².