Question

In the given figure, a is greater than one sixth of right angle, then which of the following is true?

• A. $b>{165}^o$
• B. $b<{165}^o$
• C. $b\le {165}^o$
• D. $b\ge {165}^o$

Answer 1

The correct option is B $b<{165}^o$

$a+b={180}^o$ (as given in the figure)

$b={180}^o-a\dots eqn\left(1\right)$

and $a>\frac{{90}^o}{6}\Rightarrow a>{15}^o\Rightarrow -a<-15$

adding ${180}^o$ both side, we get

$\Rightarrow {180}^o-a<{165}^o\dots eqn\left(2\right)$

From the above equations (1) and (2):

$b<{165}^o$