What is the slope of the line joining (8, 8) and (12, 6)? −2 negative one over two start fraction one over four end fraction start fraction one over two end fraction

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?

Me i'm timed ! a. -2 to 1 b. -1.5 to 0.5c. 0 to 1d. 0.5 to 1.5

What are the triple angle formulas? is it related to double angle identities?