Answer:
centre of dilation = origin (0,0)
scale factor = 3
Explanation:
In order to figure out the scale factor you just have to realise when you do a dilation, the distance between corresponding points will change according to the scale factor.
By looking at the triangle B in the graph the height is 3 units
similarly corresponding height of triangleA is 1 unit
For an dilation = large number ÷ small number
So our scale factor right over here is 3.
In order to identify centre of dilation draw a straight line from end point of height of small and large triangle and make a triangle out of this.
That straight line will be hypotenuse of the triangle and it will be exactly as large as the triangle B.