Determine which set of ordered pairs is a function.
a.
{(–1, 3), (1, 4), (–1, 5)}
b.
{(5, 3), (–6, 3), (–2, 4)}
c.
{(0.5, 1.6), (1, 1.75), (1.5, 2.3), (0.5, 3.6)}
d.
{(1, 2), (–5, 4), (3, 6), (–5, 2)}

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