In triangle ABC, angles A and C are equal, AC = 16cm, the bisector of angle B is 15cm. Find BC.

Since, by condition, the angle BAC = BCA, the triangle ABC is isosceles with the base of the AC.

Then, the bisector of the angle ABC will also be the height and median of the triangle ABC, which means that the triangle BCH is rectangular, and CH = AH = AC / 2 = 16/2 = 8 cm.

We use the Pythagorean theorem and determine the length of the BC hypotenuse.

BC2 = BH2 + CH2 = 225 + 64 = 289.

BC = 17 cm.

Answer: The length of the BC side is 17 cm.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.