What is a example of proving a geometric statement to be indirect?

An example of proving a geometric statement indirectly is using proof by contradiction. For instance, to prove that the angles in a triangle sum to 180 degrees, one might assume the opposite: that the angles sum to something other than 180 degrees. By constructing a triangle and showing that such a configuration leads to a logical inconsistency—such as creating an angle larger than a straight line—one can conclude that the original statement must be true. This method effectively demonstrates the validity of the statement through the invalidity of its negation.