# data[].attributes.body
a) He meant Quadrate AB equating to x^2 that is seen in the equation. With each of its being the value x, an undetermined value.

b)  It would have to be symmetrical on both of the sides. The halving allowing for that to occur geometrically.

c) This method is known as completing the square because we're filling in a missing piece in order to have a perfect square

# data[].attributes.body
We believe he required the 3 different species of problems to cover for the idea that any of the values could end up being negative. As each species available would lead to one of the values being negative once set equal to 0. Whether it be the square, root, or simple number.