If the area of the yard is 3a^2 and is also 7,500^2 then 3a^2=7,500^2
So we want to find what A is not 3a^2.
3a^2=7,500^2 now we square root both sides
3a=7,500 now we divide both sides by 3
a=2,500
And there you go a=2,500
Bainliest if this helped you?