Answer:

Explanation:
If the ratio of the sides is 13:14:15, we can say that the length of each side is 13x, 14x and 15x.
Then, if the perimeter is 84 m, we have:



The length of each side is:



Now, to find the area of the field, we can use the following formula:

Where a, b and c are the sides and p is the semi perimeter:

So we have that:

