Answer: Incomplete question, please edit.
Step-by-step explanation:
Undefined terms is the category its belongs to.
CD is congruent to XY, DA is congruent to YZ and AC is congruent to ZX even tho i'm not able to see properly your image
he divided each rectangle in 12 identical parts
for the first rectangle he shaded 1/3 of 12 = 4 parts
for the second rectangle he shaded 1/4 of 12= 3 parts
so 12= 3*4 leads to a minimum of 12 parts
:)
