It is 140.
70' x 19'= 1330 ft.^2
foot (a biological structure used for locomotion)
To those who use Imperial measure (e.g. America) a foot equals 12 inches. For the majority of the world a foot is a measure equivalent to about 30 cm. Historic feet have ranged from about 28 to 34 cm.
Square foot is a measure of area. Cubic foot is a measure of volume. They are not equal.