Here we can first find the area of yard and then subtract the area of vegetable garden to get the required area.
The formula to find area is given by:
Now we find area of yard:
length is 25 ft and width is 15 ft.
Area of yard = 375 ft²
Area of vegetable garden:
length = 8ft and width =8ft
So the vegetable garden is a square.
Area = 8*8
Area of vegetable garden =64 ft²
Area of backyard to be laid with grass = Area of yard-Area of vegetable garden
Area required = 375 -64 = 311 ft²
Answer : The area of backyard in which grass is to be laid is 311 square feet.