How much is the area of a land measuring 70'Length x40'widthx60'lengthx30'width?
Area is two dimensions. You've given four, defining a
hypervolume of 70x40x60x30 = 5,040,000 ft4 (hypercubic feet).
If you mean TWO areas, it's just a matter of simple
multiplication, which is left as an exercise for the student:
70x40 = ___ ft2 (sq.ft., square feet)
60x30 = ___ ft2 (sq.ft., square feet)