How did the wealth obtained by the Italian city states encouraged the start of the Renaissance?

Basically, the Rennaissance started because Italy's city-states were very wealthy merchant states that gained their wealth from trade. Rich families who monopolized that trade, like the Medici family in Florence, were able to give some of their money to fund artistic endeavors, thus starting the Rennaissance.

The Renaissance began in northern and central Italy. Part of it was because of the properity of Italian city-states. In Italy, growing towns demanded self-rule and developed into city-states. Each city consited of a powerful city and the surrounding towns and countryside. Italian city-states conducted their own trade, collected their own taxes, and made their own laws. Some city-states, such as Florence, were governed by an elected council. During the Renaissance groups of guild members, called boards, often ruled Italian city-states. Some wealthy families gained long-term control; city-states were ruled by a single family, such as the Medicis.

Trade made the Italian city-states wealthy. Italy's location on the central Mediterranean placed its cities in the middle of the trade routes. People from all over Europe came to northern Italy to buy, sell, and do their banking. Many city-states developed specializations. For example, Milan produced metal goods and armor. Genoa was a trading center for ivory and gold. Venice had hundreds of ships that controlled the trade routes in the Mediterranean sea, and silk, spices, and perfume flowed into Wenice.

The wealth of many city-states encouraged art and learning. Rich families paid for statues, paintings, beautiful buildings, and avenues to be created. They built centers of learning and hospitals. Renaissance ideas spread to the rest of Europe from the city-states of Italy.