Rhetorical situation is everything that plays a role in shaping the rhetoric; it is the principal concept of rhetoric. In other words, rhetorical situation is everything and anything that surrounds and relates to the communication/text. Although there are many, the basic elements of a rhetorical situation are the rhetor, the audience, and the text because all messages are communicated by someone, intended for someone, and assume a specific shape or form.
For example, here is a basic rhetorical situation: we (the rhetor) can communicate with our body language (text) to the person sitting next to us (audience) that we are not interested in talking by simply turning our head away. Because no rhetoric can take place without these essential elements, they are usually depicted as a triangle, with each point labeled as one of the elements, and referred to as a Rhetorical Triangle.