Question

I just need the answer the work isn't necessary

Answer 1

• 57°

Explanation:

Vertical angles theorem states that vertical angles are congruent.

Arcs EF and are intercepted by vertical angles, therefore:

• mAB = mEF = 36°

Angle addition postulate.

• mABD = mAB + mBD

Central angle has same measure with intercepted arc.

• mBD = m∠BCD = 21°

So the arc ABD is:

• mABD = 36° + 21° = 57°