you see it has 2 equal sides, so the triangle is an isosceles triangle. If the triangle is isosceles, then its 2 base angles are equal, that is, x = 79 according to the triangle property, the 3 angles add up to 180 degrees, so you take 180 degrees minus 2 * 79 degrees you get a y angle equal to 22 degrees
By definition, the point at which a median intersects the side of the triangle opposite from the vertex from which it is drawn is the midpoint of that side.
