AM^2 = bc [1 − (a^2/(b + c)^2)]
see
geometry-math-journal.ro/pdf/Volume1-Issue1/ON%20THE%20STANDARD%20LENGTHS%20OF%20ANGLE%20BISECTORS%20AND%20THE%20ANGLE%20BISECTOR%20THEOREM.pdf
or
proofwiki.org/wiki/Length_of_Angle_Bisector
Whats the length of the angle bisector AM of the triangle ABC, if AB = c,
AC = b and ∠A = α
1 answer