`DeltaABC` में, AB=BC `angleB=x^(0)` तथा `angleA=(2x-20)^(@)` हे, तब `angleB` हे|

Options

A. `54^(@)`
B. `30^(@)`
C. `40^(@)`
D. `44^(@)`

Answer

A

Explanation

According to question,

Given: AB=AC
`angleC=angleA=2x-20^(@)`
`angleB=x^(@)`
As we know that,
`angleA + angleB + angleC=180^(@)`
`(2x-20)^(@)+x+(2x-20)=180^(2)`
5x=`220^(@)`
`x=44^(@)`
`therefore angleB=44^(@)`