How can you use angle bisectors of triangles in real life situations to solve problems?
I would guess that bisecting angles and other geometrical constructs are used by architects when they are drafting the designs of buildings.
However, more and more of the constructs are being done by machines. Even sewing is not as much done by hand these days as it has been automated with the design process done by computers. However, the programmers who write the programs for the computers which do drafting and sewing design need to know how to bisect angles. Someone always needs to know these things.
Will you ever have a job where you need to know this? The probability is that you will not.