Area = (length) x (width) = (25mm x 12mm) = 300 square millimeters
You can't convert 'square millimeters' to feet. One is a unit of area,
but the other is a unit of length.
You can convert square millimeters to square feet, though.
(300 mm²) x (1 ft / 304.8 mm)² = 0.00323 square foot (rounded)
