Use the Pythagorean theorem in mathematics to answer this question. The fallen lotus is a right-angled side of a triangle, with a length of 0.5 feet. The other right-angled side is the neck of the water, which is the depth of the water. The hypotenuse is the distance from the head of the lotus to the base of the lotus. It is stated in the poem to be 2 feet. The answer obtained from the Pythagorean theorem is: 3.75.