how can you write as in circle pie 1ft and 6in
30
Depends on the location you take the measurement at: it can go from 0.25" (1/4" x 1ft /12" x 1 fathom/6 feet = 0.0034 fathoms), at the beach, to 7 miles deep (7x 5280/6 = 6160 fathoms) in the Marianas trench.
15 feet.
30 feet
5 feet.
21 feet.
Only one foot.
31,680 feet.
5,280 feet
Usually by feet. 1ft floods aren't much a deal. 2ft floods might be a pain. 3ft floods could mean fatal currents. 4ft and above GO INSIDE IT'S HORRIBLE! Like that.
1/12 feet go in an inch (and 12 inches go in a foot)
5,280 feet = 1 mile