Which characteristics do cell membranes and cell walls have in common?
they are selectively permeable and aid in communication.
they contain mostly cellulose and are selectively permeable.
they store carbohydrates and aid in communication.
they are rigid structures and contain mostly cellulose.

Both protexts the organisms' organelles which are inside the cell. 
Animal Cell: Cell Membrane
Plant Cell: Cell Wall
Cell wall is present only in plants, it is not found in all organisms. Compared to the cell membrane, a cell wall is thick and has a rigid structure. You can see it in a light microscope, because it is visible. It serves as the protective cover that surrounds the plasma membrane in a plant cell. Cell membrane is composed of lipids. Cell walls can be made up of cellulose or peptidoglycan or chitin.

Remember soh-cah-toasoh: cah: toa: now, looking at the picture we can see that we have an angle, the hypotenuse and want to find the value of the adjacent side to the angle. so we use cah to find the adjacent angle. plug in what we have: we need to solve for x now so we get it by itself on one side: plug this into your calculator and you'll find that: