Greg is trying to push a box of books across the floor of his room. the box of books doesn't move because the forces on the box are when his little brother walks in and starts pushing with him, the box begins to slide across the floor. his brother's pushing, combined with his, makes the forces on the box a. unbalanced; balanced b. balanced; unbalanced c. shifting; still d. not acting on the box; moving

Given: lines a and b are parallel and line c is a transversal. prove: 2 is supplementary to 8 what is the missing reason in the proof? statement reason 1. a || b, is a transv 1. given 2. ∠6 ≅ ∠2 2. ? 3. m∠6 = m∠2 3. def. of congruent 4. ∠6 is supp. to ∠8 4. def. of linear pair 5. ∠2 is supp. to ∠8 5. congruent supplements theorem corresponding angles theorem alternate interior angles theorem vertical angles theorem alternate exterior angles theorem