Final answer:
Monopolies are not economically efficient. They result in a loss of overall surplus compared to perfectly competitive markets.
Step-by-step explanation:
A monopoly is not economically efficient compared to a perfectly competitive market. In a perfectly competitive market, there are many sellers and buyers, leading to allocative efficiency where resources are allocated optimally. However, a monopoly has no competition and therefore has the ability to control prices and restrict output, resulting in inefficiency.
Compared to a perfectly competitive market, a monopoly would reduce consumer surplus and producer surplus, resulting in a loss of overall surplus. The shaded area in the triangle drawing tool would represent this change in surplus, and it would be labeled as 'Loss of Surplus'.