Believability Of a speaker is highly dependent on supporting materials for that are

credible

Explanation:

Public speaking refers to the process of communicating the ideas to the live audience by a specific speaker. A group of listeners and a speaker are its main elements. There are various aspects on which a speaker is required to focus while delivering a public speech. The supporting materials for or against the topic that are provided by the speaker helps in building a strong argument before the listeners. Also, the belief in the speaker is established with the credibility of the supporting materials.

there are several different forms of presenting this; each has a very specific format. plays have a very simple format; teleplays, for television shows, or screenplays, for movies, have more complex and strict rules for formatting.

drama

the first of these to be written for the express purpose of being performed were created by the greeks. many of our modern terms derive from greek origins.

comedy

in the greek sense, a play that doesn't end in death. in modern usage, refers to a play that is humorous.

tragedy

in the greek sense, a play that ends with the death of at least one of the main characters. in modern usage, refers to a play that doesn't have a happy ending.