In the acute triangle ABC, BC = 12, the area of triangle ABC is 12, the two moving points m and N slide on the sides AB and AC respectively, and Mn ‖ BC, take Mn as the side, make a square mpqn downward, let its length be x, and the area of the common part of square mpqn and triangle ABC is y (Y > 0) (1) Height ad on edge BC in triangle ABC=____ (2) When x=____ PQ just falls on the side BC (3) When PQ is outside the triangle ABC, the function of Y with respect to X is (indicate the value range of x)

In the acute triangle ABC, BC = 12, the area of triangle ABC is 12, the two moving points m and N slide on the sides AB and AC respectively, and Mn ‖ BC, take Mn as the side, make a square mpqn downward, let its length be x, and the area of the common part of square mpqn and triangle ABC is y (Y > 0) (1) Height ad on edge BC in triangle ABC=____ (2) When x=____ PQ just falls on the side BC (3) When PQ is outside the triangle ABC, the function of Y with respect to X is (indicate the value range of x)

1 / 2 bottom * height equals area, height = 12 / 12 * 2 = 2
Use the area to do: the square of X + 1 / 2x (2-x) + 1 / 2x (12-x) = 12 to find x = 12 / 7
12 / 7X (x is greater than 12 / 7)