Median BD is drawn in an isosceles triangle ABC with base AC. find the angles ABD and ADB if ABC = 78.

Since triangle ABC is isosceles, AB = BC, its median ВD is also the height and bisector of the triangle.

Then the triangles AВD and ВСD are rectangular, and the angle AВD = СВD = ABC / 2 = 78/2 = 39.

Since the AВD triangle is rectangular, the ADВ angle = 90.

Answer: Angle ADВ = 90, angle ABD = 39.



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