Because thee dimensions of ΔRAH is twice as large as corresponding dimensions of ΔEAC,
|RA|=2|EA|=2*3.5=7
|AH|=2|AC|=2*6=12
So, we have that 2 corresponding sides are in proportion and angle between them =90⁰, so the angle between them are congruent,
we can use SAS to prove that these triangles are similar.
