In an isosceles triangle ABC, the median BM is drawn to its base AC, and the angle MBC = 40 °. Find the angles of triangle ABC.

Since the triangle is isosceles BM – medinaa, bisector and height. If the BM is the height, then the angle of the BMC is 90 degrees. Since the sum of the angles of the triangle is 180 degrees, we find the angle C from the BCM triangle. angle B is equal to 40 degrees by condition, angle M is 90, which means angle C is equal to 180-90-40 = 50. Since triangle ABC is isosceles, it means that the angles at the base are equal, so angle A = angle C = 50 degrees. Since VM is equal to the bisector, it divides the angle in half. If half of the angle is 40, then ABC is 80 degrees.