Crossing over is a process that occurs only in meiotic division in sexually reproducing organisms. It is the process whereby the segments of a gene are exchanged between the non-sister chromatids of homologous chromosomes.
Due to this crossing over process that occurs in prophase I of meiosis, the alleles of a chromosomes are recombined to ensure genetic diversity. Hence, according to this question, crossing over results in additional genetic variation during meiosis because it allows the recombination of genetic information.
The angle bisector theorem is commonly used when the angle bisectors and side lengths are known. It can be used in a calculation or in a proof. An immediate consequence of the theorem is that the angle bisector of the vertex angle of an isosceles triangle will also bisect the opposite side.
