80 yards are 240 feet. Forget the word "linear". All length measures are linear.
You cannot. Linear feet are a measure of distance, square feet are a measure of area. The two measure different things and it makes no sense to try to convert from one to the other.
That is impossible, because linear miles are a 'length' and square feet cover an 'area'.
you don't. that's like asking how many dollars are in 10 feet. the units "linear feet" and "square feet" represent two totally different types of quantities. if you have a rectangle made up of 216 linear feet, the area (in square feet) could be practically anything. If the sides are 50 and 58, the perimeter is 216 linear feet and the area is 2,900 square feet. But if the sides are 10 and 98 feet, the perimeter is still 216 linear feet, while the area is now 980 square feet.
You cannot convert area to linear measurement.
is 8 feet 8 feet in linear feet
You don't. You can't convert that.
how do I convert 80 feet into square footage?
You want to convert an area into a length or distance. That is not possible.
You don't convert that. It just doesn't make sense.
Not possible to convert a linear measure to an area measure.
Cubic inches are a measure of a volume. "Linear" feet are normal feet as a measure of length or distance. You cannot convert one into the other.
Multiply the length by the width.
Divide feet by 5,280 to get miles.