The shapes/dimensions for plots of house should be square or rectangular. A square plot is considered the best since it is said to bring all the positive entities equally. The Tirupathi Tirumala temple is the best example of a beautifully built structure in an accurately square plot. The results of course are evident!
If the plot is rectangular, it is better that the longer sides are aligned north to south rather than west to east. A rectangular plot with dimension 1: 2 is auspicious as well.
The northeast side of the land should be the lowest side. The land should either slope down toward the north or east, but not toward the west or south. Land sloping north brings riches, sloping east brings good fortune, sloping south brings ruin, and sloping west brings financial loss.It is auspicious if tall buildings or hills do not obstruct the north, northeast, and east sides of the land. Do not purchase land with such obstructions to those sides because the sun's rays will be blocked.
The below image explains precisely what is discussed above:
This question is also relevant to what you have asked. Do read http://community.vastudekho.com/705/36-23-mera-plot-area-hai