Why this made the colonists angry?
After the Boston Massacre, colonists were largely outraged at what they saw as a vicious attack on unarmed civilians. Supporters of the Patriot movement were quick to capitalize on this, and they released engravings and written accounts of the incident designed to portray the British soldiers in the most negative light possible.

Why the colonists protested?
Boston’s anger at British taxes and policies exploded at town meetings. These meetings drew thousands of people who could not fit inside the usual town meeting place at Faneuil Hall, and instead were held at Old South Meeting House, the largest gathering place in Boston.

 How the colonists protested?  and   How did the  British react?
The ultimate response of the British government to these protests was to repeal the Townshend Acts.  They revoked all of the taxes imposed by these acts except for the tax on tea.When the Townshend taxes were imposed, there was a great deal of protest in the colonies.  The British reacted to this with some degree of force.  They sent troops to Boston, which eventually led to the Boston Massacre.  However, the force did not work and did not last.  The colonists’ non-importation efforts started to hurt British merchants.  These merchants put enough pressure on the government that they eventually repealed almost all of the taxes.

What was the outcome of the protest?
The Massacre trials ended quietly. Samuel Adams wrote several articles in the Boston Gazette during December, 1770, under the pseudonym "Vindex," that accused the soldiers of escaping with blood on their hands. But the mood had changed in Boston since the Massacre. He turned his attentions to keeping the memory of the Massacre alive, organizing annual commemorations on March 5, a tradition that lasted until 1783.

The bolded words are all secondary person propaganda because it is not using words but describing from other that was not involved or witnessed it. 

(above)This is a primary source because it is a painting of the british tea party and was the actual one.

This link is the cite where I got the info of what happened at the Tea Party

http://www.history.com/topics/american-revolution/boston-tea-party
What made the colonists angry?   
King George believed that the colonists had the rights to pay the taxes that made them pay the taxes for the debt that left after the French and Indian war and bringing mens which is not cheap.
 The passage
http://historyisfun.org/pdf/tea-
'overboard/why_were_the_american_colonies_unhappy_with_the_british_government.pdf
why the Boston Tea Party was very important in history of U.S
This action, part of a wave of resistance throughout the colonies, had its origin in Parliament’s effort to rescue the financially weakened East India Company so as to continue benefiting from the company’s valuable position in India. The Tea Act(May 10, 1773) adjusted import duties in such a way that the company could undersell even smugglers in the colonies. The company selected consignees in Boston, New York, Charleston, and Philadelphia, and 500,000 pounds of tea were shipped across the Atlantic in September.
This is also a secondary person propaganda because it is not using quotes of a person that witnessed it or was involved in that action.

https://www.britannica.com/event/Boston-Tea-Party

(above and below images) Those images are all first person propaganda because it is a drawing of someone who was involved in the happening of that time and was passed through time.
http://www.history.com/topics/american-revolution/boston-tea-party