1B. Dan cut 18 pieces of sandwiches from a single loaf of bread. Each piece
was of a foot long. What was the shortest length the loaf could have been?
(A) 17 feet
(C) 90 feet
(B) 18 feet
(D) 10 feet

Statements reasons 1. ab ? cd; ad ? bc 1. given 2. ac ? ac 2. reflexive property 3. ? adc ? ? cba 3. ? 4. ? dac ? ? bca; ? acd ? ? cab 4. cpctc 5. ? dac and ? bca are alt. int. ? s; ? acd and ? cab are alt. int. ? s 5. definition of alternate interior angles 6. ab ? cd; ad ? bc 6. converse of the alternate interior angles theorem 7. abcd is a parallelogram 7. definition of parallelogram what is the missing reason in step 3?