a) 40000 m square

b) 20000 m square

c) 10000 m square

d) 800 m square

correct answer is: c) 10000 m square

**Explanation**

We know,

\rightarrow Perimeter of a square = 4\ \times\ side

\rightarrow Area of a square = side^2

According to the question,

\left(4\ \times\ side\right)\ =400\ m

\rightarrow\ side\ =\ \frac{400}{4}\ m

\therefore side\ =\ 100\ m.

\therefore Area of the square = 100^2 or (100 \times 100) m^2

= 10000 m^2 **Ans:** Area of the square = 10000 m^2