I need help, please! ASAP.

Formula for percent change is C = {x_2 - x_1}/{x_1}  

C=relative change

x_1=initial value

x_2=final value

Step-by-step explanation:

<_> daddy

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⭐