Question

If oblique ΔABC has side b=32 in., side c=45 in., and included ∠A=56° , then what is the length of side a? (1 point)38 in.2,440 in.1,439 in.49 in.

Answer 1

Use the Law of Cosines: a^2 = b^2 + c^2 - 2bc cos A
= 32^2 + 45^2 - 2(32)(45)cos56°
= 1024 + 2025 - 2880(0.55919...)
≈ 3049 - 1610.48 = 1438.52

So a ≈ sqrt(1438.52) ≈ 37.92 in ≈ 38 in.