Question

Let the angles `A , Ba n dC` of triangle `A B C` be in `AdotPdot` and let `b : c` be `sqrt(3):sqrt(2)` . Find angle `Adot`
A. `75^(@)`
B. `60^(@)`
C. `45^(@)`
D. `30^(@)`

Answer 1

Correct Answer - A
We have,
`2B=A+CimpliesB=60^(@)" "[because A+B+C=180^(@)]`
Now,
`b:c=sqrt(3):sqrt(2)`
`impliessinB:sinC=sqrt(3):sqrt(2)`
`implies (sinB)/(sqrt(3))=(sinC)/(sqrt(2))implies(sin60^(@))/(sqrt(3))=(sinC)/(sqrt(2))`
`implies sinC=(1)/(sqrt(2))impliesC=45^(@)`
`therefore A+B+C=180^(@)impliesA=75^(@)`