The unit square ABCD where A(1,0), B(1,1), C(2,1), D(2,0)

i) A line, l , passing through the origin with gradient m, cuts the sides AB and CD at P and Q respectively

is the answer to this part

i am unsure on how to approach these two parts any help would be most appreciated.

ii) For what value(s) of m does the line, l, divide the area of the square in the ratio 2:1??

iii) Another like, k, passes through the origin with gradient, n, and cuts the square through the sides AB and Bc at S and T respectively.

Show that it is not possible for k to divide the area of the square in the ratio 2:1

Thanks Nath