This is normal. This problem is an interlocking solution. Intention means that you can find the maximum range of coordinates of point C through a problem, and then determine a coordinate point that can make the triangle area the largest according to the coordinates of point C and known conditions. That's just an external question, as long as the answer X calculated by the questioner is greater than 0 and less than 4; Y is greater than 0 and less than 3, you can set it at will, and adding the square factor in it only makes the problem more difficult. This problem can be solved in ten minutes. Is the picture below better or the same?