The triangle abc square at A, the altitude AH. The circle with center H. radius HA intersects the line AB at D and cuts AC at E. The median AM of the triangle ABC cuts DE at I. Prove that: a) D, H, E are collinear b) Prove that BCDE insider. Determine the center O of this circle. c) Prove that AM is perpendicular to DE when you are done, pls send me the picture. and can you translate all of it to Vietnamese pls ?​