How do i find the coordinate of point D given that the length of AD is 5 and slope is $4/3$. I guess we should be able to write an equation which takes into account the length of AD which is 5 and the slope which is 4/3 to solve the coordinate point D.
Note: One my friends tried answering my above question using vector, something which i havent studied yet. So please give me solution in a more simple math.

Note that to go from B to C, you go to the left 4 units and up 3 units. Since this a parellelogram, to go from A to D you must do the same. (Edited to add: This is based on the drawing provided. Based on the text, you would say left 4 units and down 3 and would expect the drawing to be in the third quadrant, or lower left, where both values are negative).