Respuesta :

mhanifa

Answer:

  • D. 70°

Step-by-step explanation:

∠BEC is supplementary with ∠BEA

Find the measure of ∠BEA

  • m∠BEA = 1/2(mCD + mAB)
  • m∠BEA = 1/2(120° + 100°) = 110°

Supplementary angles sum to 180°

  • m∠BEC + m∠BEA = 180°
  • m∠BEC = 180° - 110° = 70°

Correct choice is D