Bryan is making chocolate chip cookies. He has a bag of chocolate chips. He uses 12 of his total
amount of chocolate chips in the first batch and 1/4 of
his total amount in the the second batch. If he used 3
cups of chocolate chips, how many cups of chocolate
chips were in the bag to start?

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?