Any two rectangles similar

False they are not all similar because they may all have congruent angle but they are not similar for example a rectangle 2 by 4 and 4 by 8 are but 9 by 3 is not similar.

The Scale factor for 9 by 3 and  2 by 4 is 2.25 but that does not match with 1.5

9/4=2.25        3/2=1.5

The Scale factor for 4 by 8 and  2 by 4 are both 2

4/2=2  8/4 = 2

Another  thing is they most have the same general shape

all rectangles are not the same general shape

Any two equilateral triangle are similar

True because they fit all the rules the corresponding angles  are congruent because equilateral triangle must  have a 60 degree angles

all the scale factors are the same they can change to because the  equilateral triangles can change to be the same