An indirect proof starts with the assumption that the statement we are trying to prove is not true.
The lines are not parallel.
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An indirect proof starts with the assumption that the statement we are trying to prove is not true.
In this case, the conclusion of the conditional statement is that the lines are parallel. The negation of this statement is that the lines are not parallel.
The lines areparallel.
⇓
The lines are notparallel.
Finally, we can state the assumption we would make to start the indirect proof.
Assumption:
The lines are not parallel.
