`A B C D` is parallelogram. If the coordinates of `A , B , C` are `(-2,-1),(3,0)` and `(1,-2)` respectively, find the coordinates of `Ddot`

Explanation

Let `(x,y)` are the coordinates of point `D`.

As, `ABCD` is a parallelogram,

`vec(AD) = vec(BC)`

`:. (x+2)hati +(y+1) hatj = -2hati +(-2)hatj`

`:. x+2 =- 2 and y+1 = -2`

`=> x= -4 and y =-3`

`:.` Coordinates of point `D` is `(-4,-3)`.