
Patrick B. answered 02/07/19
Math and computer tutor/teacher
Angle CAB = angle DAC is shared (reflexive property
angle ABC = angle ACD = 90 are congruent right angles
By congruent angle theorem,
angles CAB + CBA = 90 = DAC + DCA
So, CBA = DAC after subtracting CAB=DAC from both sides
Therefore, corresponding angles are congruent, which proves the triangles are similar