The formula for finding area is l * w
Since a square has all sides the same length, we need to multiply 40 by 40.
40 * 40 = 1,600 ←
Check work by dividing 1,600 and 40:
1,600 ÷ 40 = 40
Your answer is Option D. 1,600 km². (The answer wouldn't be option C as it is referring to perimeter, not area)
The area of the square is 1,600 km².
I hope this helps! :)
