Question

What is the measure of Arc CB?
84
60
90
67

Answer 1

60°.

Explanation:

1. DB is diametre, then

2. m∠BCD=90°, then

3. m∠BDC=m∠BCD-m∠CBD=90-60=30°, then

4. finally, Arc(CB)=2*m∠BDC=60°.