Question

In the figure given above, $\angle DCE={20}^{\circ },\angle EDC={60}^{\circ }.$ Find $\angle CED.$

• A. $\angle CED={100}^{\circ }$
• B. $\angle CED={90}^{\circ }$
• C. $\angle CED={60}^{\circ }$
• D. $\angle CED={160}^{\circ }$

Answer 1

The correct option is A

$\angle CED={100}^{\circ }$

In $\Delta CDE,$
$\angle DCE+\angle CDE+\angle DEC={180}^{\circ }$ [Sum of angles of a triqangle is ${180}^{\circ }$]
${20}^{\circ }+{60}^{\circ }+\angle CED={180}^{\circ }\Rightarrow {80}^{\circ }+\angle CED={180}^{\circ }\Rightarrow \angle CED={180}^{\circ }-{80}^{\circ }\Rightarrow \angle CED=\angle {100}^{\circ }$