If a triangle has three sides with the lengths 20, 16, and 12, what are the angles?

angle a = 53.13°

angle b = 36.87°

angle c = 90°

Step-by-step explanation:

The following is one way to perform the calculation. It may not be the best way.

Calculates ∠A, ∠B, ∠C based on given a, b and c.

∠A = arccos(  b2 + c2 - a2 2bc )

= 0.9273 rad = 53.13° = 53.13°

∠B = arccos(a2 + c2 - b2 2ac )

= 0.6435 rad = 36.87° = 36.87°

∠C = arccos(a2 + b2 - c2 2ab )

= 1.5708 rad = π/2 = 90°

< 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⭐