In ` DeltaA B C ,\ if\ a=8,\ b=10 ,\ c=12\ a n d\ C=lambdaA ,\ ` find the value of `lambdadot`

Explanation

We may know from sine rule that,

`operatorname{CosA}=frac{b^{2}+c^{2}-a^{2}}{2 bc}=frac{100+144-64}{240}=0.75`

SoA `=cos ^{-1} 0.75=41.40^{0}`

Now

`cos C=frac{b^{2}+a^{2}-c^{2}}{2 ab}=frac{100+64-144}{160}=0.125`

So `C=cos ^{-1} 0.125=82.81^{0}`

Now it is given that,

`angle C=lambda angle A}`

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