Ecological footprint is the amount of needed to supply a person or an area with renewable resources and that are needed to absorb and recycle the waste and pollution produced by such resource use.

Biological Productivity.

Explanation:

As the term ecological footprint means the impact of one's foot over the ecological systems. Its also seen as the foot of consumption,  It is the ability of the earth or the ecological system to produce the demanded stuff that is required for the existence and survival of the organisms, that compete for biological space. The term in short also is used to define biocapacity. This Also states the biological component to absorb the carbon content created by the organism  The biological capacity in polar decreases and increases in trophic levels. Similarly,  the oceanic productive and biological carrying capacity is impacted by this demand cycle. Related to the food chain and food web. Thus it's essential that this productivity is maintained and is needed as an energy source to absorb and recycle the wastes and pollution produced by continuous resource use. The primary productivity is measured by autotrophic level and secondary productivity is measured by heterotrophic level.

H=   2(area/a+b)h= 2(144/a+b)h= 2(144/18+18)h= 2(144/36)h= 2(4)h=8