A waterworks decided to build a pumping tower by the river to supply water to a and B reservoirs. Please design a line for it to make the length of the water pipe shortest Before 10 o'clock, it's overdue

A waterworks decided to build a pumping tower by the river to supply water to a and B reservoirs. Please design a line for it to make the length of the water pipe shortest Before 10 o'clock, it's overdue

The equivalent is to connect AB as the intersection of the middle vertical line and the river. The shortest is to make a mirror symmetrical with respect to the river, and then connect the mirror image of a and B, and the intersection of the line and the river