I need help with my math

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?

Table which ratio is equivalent to 3: 7? 6: 7 3: 21 24: 56 15: 30

If the endpoints of the diameter of a circle are (8, 6) and (2,0), what is the standard form equation of the circle? a) (x + 5)2 + (y + 3)2 = 18 (x + 5)2 + (y + 3)2 = 3.72 (x - 5)2 + (y - 3)2 = 18 d) (x - 5)2 + (y - 3)2 = 32