The number 3.14 is a rounded value of the mathematical quantity π. if you replace 3.14 with π, what is the exact formula for the circumference in terms of the diameter, d, and in terms of the radius, r?

 the  radius = 3.14*2r= 6.28r.i got this answer from user

circumference = πd = 2πr

Step-by-step explanation:

< coa = 150 ( given)

as ba and bc are tangents

so oc and oa is perpendicular to cb and ab respectively because in circle normal passes through centre

so in quadrilateral oabc

< coa + < oab + < ocb + < abc = 360

150 +90+90 + < abc = 360

330 + < abc = 360

< abc = 360 -330 = 30

so < abc = 30

⭐dhruv⭐