isosceles – AB = BC, the coals at the base are even (angle A = angle C) From point B, the height BD is lowered to the side of AC, and the height always falls at a right angle. Thus, BDC is a right-angled triangle. angle BDC = 90. ВD (height) = X (x), and BC = 2x (two x) according to the task In a right triangle, if the leg (BD) = half of the hypotenuse (BC), then it lies opposite an angle of 30 degrees, then the angle C = 30. Into the treug. ВDС cut С = 30, D = 90, and В = 180- (С + D) = 180-30-90 = 60 In triangle ABC, angle А = angle С = 30, and angle В = 180-А (30) -C (30) + DВС (60) = 120
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.