Answer and Explanation
Your Answer is
Correct Answer is J
Explanation
Because of the vertical angle, so ∠ECF=∠BCA=31, and because AB=BC, so ∠B=180-2×31
Your Answer is
Correct Answer is J
Explanation
Because of the vertical angle, so ∠ECF=∠BCA=31, and because AB=BC, so ∠B=180-2×31