Taxes and welfare

Consider the market for mountain bikes. The following graph shows the demand and supply for mountain bikes before the government imposes any taxes.

First, use the black point (plus symbol) to indicate the equilibrium price and quantity of mountain bikes in the absence of a tax. Then use the green point (triangle symbol) to shade the area representing total consumer surplus (CS) at the equilibrium price. Next, use the purple point (diamond symbol) to shade the area representing total producer surplus (PS) at the equilibrium price.