在三角形ABC中，已知如下条件，a=15cm,b=10cm,A=60°解三角形
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a/sinA = b/sinB
sinB = b * sinA/a = 10 * sin60° /15 = 2/3 * √3/2 = √3/3
cosB = √(1-1/3) = √6/3
sinC = sin(180°-A - B) = sin(A+B)
= sinAcosB+cosAsinB
= √3/2 * √6/3 + 1/2*√3/3
= √2/2 + √3/6
c = sinC/sinA *a = 15 * (√2/2 + √3/6)/(√3/2) = 5 * (√6 + 1) ∽17.25 cm
sinB = b * sinA/a = 10 * sin60° /15 = 2/3 * √3/2 = √3/3
cosB = √(1-1/3) = √6/3
sinC = sin(180°-A - B) = sin(A+B)
= sinAcosB+cosAsinB
= √3/2 * √6/3 + 1/2*√3/3
= √2/2 + √3/6
c = sinC/sinA *a = 15 * (√2/2 + √3/6)/(√3/2) = 5 * (√6 + 1) ∽17.25 cm
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