Which of the following statements are true? Select all that apply.
A. 27 is a perfect cube.
OB. 121 is a perfect square.
C. 9 is a perfect cube.
D. 21 is neither a perfect square nor a perfect cube.
OE. 2,197 is both a perfect square and a perfect cube.

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