Question

I need help Circle P is below

Answer 1

20y-11+4y+6+7y-7=360
31y-12=360
31y=360+12
31y=372
y=372/31=12

BC=BA+AC=4y+6+7y-7=11y-1
BC=11*12-1=131⁰

Answer 2

1. remember all of them add up equal to 360 degree.
2. add all of them up together
$(4y + 6) + (7y - 7) + (20y - 11) = 360$
3. combine like term then solve for Y
4. you will figure the arc measure of BC when you get answer for Y.