How are the functions of the cytoskeleton and the cell wall similar?

Both organelles are involved in the support of the cells.

The cytoskeleton works like the skeleton and muscles of our body. It is a set of fine, microscopic filaments and tubules of proteins present in the cytoplasm of cells.
It supports and shapes the cell allowing its movement and transport of substances.

The cell wall also protects the cell and also helps shaping it. In plant cells, it consists of polysaccharide cellulose microfibrils and often the plant cells are often turgid, so the cell wall assists in cell support preventing it from bursting.