Question

The supplement of the complement of the one third of a right angle is

• A. ${110}^{\circ }$
• B. ${120}^{\circ }$
• C. ${130}^{\circ }$
• D. ${140}^{\circ }$

Answer 1

The correct option is B ${120}^{\circ }$

Let the required angle be $x$.

According to the question,

$\Rightarrow$ $({180}^o-x)=({90}^o-\frac{1}{3}\times {90}^o)$

$\Rightarrow$ ${180}^o-x={90}^o-{30}^o$

$\Rightarrow$ ${180}^o-x={60}^o$

$\Rightarrow$ $x={180}^o-{60}^o$

$\Rightarrow$ $x={120}^o$