Answer:
Width= 120 ft
Length= 285 ft
Step-by-step explanation:
W= width and (3w-75)= length since it's 75 less than 3 times the width
w+w+(3w-75)+(3w-75)=810
8w-150=810
8w=960
w=120
So the width is 120 ft
Then substitute the 120 in for w in the length
L= 3(120)-75
L=360-75
L=285
So the length is 285 ft
You can check because 120+120+285+285=810, and because 120×3-75=285!