Question

What is the value of $a+b$?

• A. $120$
• B. $180$
• C. $60$
• D. None of these

Answer 1

The correct option is B $180$

From diagram, we can say

$a={180}^{\circ }-{120}^{\circ }={60}^{\circ }$

and $b={180}^{\circ }-{60}^{\circ }={120}^{\circ }$

Therefore, $a+b=60+120={180}^{\circ }$