Keeps in heat, protects us from radiation, provides oxygen, and protects us from objects coming towards the earth.
The answer of perimeter to this question is 36
The model represents Photosynthesis. Light, carbon dioxide, and water are the reactants. The products will be Sugar and Oxygen. Photosynthesis releases oxygen and glucose. Which is the energy that living things need to survive.
The answer would look something like this. (sorry for the ugliest diagram ever.)