Answer:
The arc measure of BC is 64
Step-by-step explanation:
1. Calculate the full circumference of the circle
C=2pir
=2pi(18)
=36pi
2. Figure out the arc measure
arc length/circumference=arc measure/degrees in a circle
14pi/36pi=arc measure/360 (solve for arc measure)
14pi/36pi *360=140
The measures of BC and CA add up to the measure of BA
mBC +76=140
BC=64