The area of the base of a prism is 21 cm2. the perimeter of the base is 20 cm. the height of the prism is 8 cm.. what is the surface area of the prism? .

the reason why your question keeps getting deleted because this is not a school related question : )

i will answer your question though.

i never tried church's

< 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⭐