(1⼀2)在三角形ABC中,角A、B、C的对边分别为a、b、c,角A,B,C成等差数列且sinA=2分之根号2,边a长为...

2025-03-01 05:29:14
推荐回答(3个)
回答1:

角A,B,C成等差数列,则B-d+B+B+d=180°,d是公差,B=60°,
sinA=√2/2,A=45°,
根据正弦定理,b/sinB=a/sinA,b/(√3/2)=1/(√2/2),
b= √6/2.

回答2:

A+B+C=π
A+C=2B
B=π/3
sinA=√2/2
a/sinA=b/sinB
b=sinB/sinA=√3/√2 >a

cosA=√2/2 cosB=1/2
sinC=sin(A+B)=sinAcosB+sinBcosA=(√2/2)(√3/2+1/2)

回答3:

sinA=2分之根号2,
∴A=45
,角A,B,C成等差数列
∴B=60,C=75
b=a/sinA*sinB=1/(√2/2)*√3/2=√6/2