Maths help Watch
I think this is how you do it? I may be wrong tho.
A = the original triangle
B = the final triangle after the 2 transformations
1 = the 1st transformation, 90 degrees anticlockwise on the point E.
After finding that I connected the corresponding points of triangle 1 to B , all 3 connect to one single coordinate (-1,0). So triangle 1 was enlarged on point (-1,0) with a scale factor of -2.