Question

Find the value of $b$ in the figure given below.

• A. ${90}^{\circ }$
• B. ${20}^{\circ }$
• C. ${120}^{\circ }$
• D. ${100}^{\circ }$

Answer 1

The correct option is D ${100}^{\circ }$

${30}^{\circ }+b+{50}^{\circ }={180}^{\circ }$ {sum of angles on a straight line is ${180}^{\circ }$}
$b={180}^{\circ }-{30}^{\circ }-{50}^{\circ }$
$b={180}^{\circ }-{80}^{\circ }$
$b={100}^{\circ }$