The perimeter of the rectangular stadium is 3 km. The width of the stadium is 200 m. Find the area of the stadium.

The area of a rectangle (S) is the product of its length (a) and width (b): S = a * b.
To calculate the area of a given rectangular stadium, you need to find its length.
The length can be found by knowing the perimeter and width of the stadium:
P = a + a + b + b = 2a + 2b – stadium perimeter,
2a = P – 2b;
a = (P – 2b) / 2 is the length of the stadium.
Let us calculate the length of the stadium if P = 3 km = 3000 m, b = 200 m:
a = (3000 – 2 * 200) / 2 = (3000 – 400) / 2 = 2600/2 = 1300 m.
Then the stadium area is:
S = 1300 * 200 = 260,000 m ^ 2 = 0.26 km ^ 2.
Answer: S = 260,000 m ^ 2 = 0.26 km ^ 2.