For this you use the distance formula of d = (square root of) (x2-x1)^2 + (y2-y1)^2
Using this and the points (-3,0) and (0,4) the distance for the short side is 5.
The points (0,4) and (8,-2) made the distance for the long side 6.
So 5+5+6+6=22
Perimeter=22
