The base of a rectangle is a length and does not have any area. Therefore, the area can not be calculated. read more
The “base” is one of the sides. The area of a rectangle (or any parallelogram) is “base x height”. If it is a 3-D shape, you could be referring to a prism or pyramid with a “rectangular base”. This means the 2-D shape of the base is that of a rectangle. read more