`DeltaABC` में, `angleABC=5 angleACB` तथा `angleBAC=3 angleACB` हे, तब `angleABC=?`

Options

A. `130^(@)`
B. `80^(@)`
C. `100^(@)`
D. `120^(@)`

Answer

C

Explanation

According to question,
`(angleABC)/(angleACB) = 5/1` , `(angleBAC)/(angleACB) = 3/1`
`therefore angleABC=180^(@)-120^(@)`
`angleABC=60^(@)`
`angleACB= 180^(@)-105^(@)`
`angleACB=180^(@)-105^(@)`
`angleACB=75^(@)`
`therefore angleABC+angleACB+angleBAC=180^(@)`
`angleBAC=180^(@)-75^(@)-60^(@)`
`angleBAC=45^(@)`