Question

which of the following best describes an indirect proof? assume a statement true and then show it must be false. just accept a statement as true. use definitions and postulates to deduce a conclusion.

Explanation:

An indirect proof (also known as proof by contradiction) works by assuming the opposite of what we want to prove (assuming a statement is true, where the statement is the negation of the actual conclusion we want) and then deriving a contradiction, which shows that the assumed statement must be false, thus proving the original conclusion is true. The other options: "Just accept a statement as true" is not a proof method, and "Use definitions and postulates to deduce a conclusion" is a direct proof approach.

Answer:

A. Assume a statement true and then show it must be false.