Question

An angle is $20°$ more than three times the given angle. If the two angles are supplementary, then the angles are

• A. $\frac{70°}{4},\frac{290°}{4}$
• B. $40°,140°$
• C. $60°,120°$
• D. $40°,80°$

Answer 1

The correct option is B

$40°,140°$

Explanation for the correct option:

Option (B): $40°,140°$

Let one angle is $a$.

Then, the other angle$=3a+20°$

$\Rightarrow a+3a+20°=180°$

$\Rightarrow 4a+20°=180°$

$\Rightarrow 4a=160°$

$\Rightarrow a=40°$

Thus, the other angle $=3a+20°=140°$

Therefore, option (B) is correct.