Which diagram can be used to prove △ABC ~ △DEC using similarity transformations? Triangle A B C is rotated about point C and then is dilated to form smaller triangle C E D. Triangle A B C is reflected across side A C and then is dilated to form smaller triangle C E D. Triangles A B C and C E D have different angle measures. Right triangle A B C is shown. Line segment D E is drawn near point C to form triangle D E C.