which of the following are not always similar?  A.two rectangles B two circles C two squares D two  isosceles right angled triangle 

Please find below the solution to the asked query:

From given options we know :  all rectangles are similar to each other and same for " Circles " and for " Squares "  as well but we can't say that about " Isosceles triangle " ,

Here we have : isoscles right angled triangle and they also similar to each other as they always have angles ( 45$°$ , 45$°$ and 90$°$ )

So

None of the given options we can say that two are not similar .

Hope this information will clear your doubts about topic.