question_answer

In the given figure, \[\mathbf{AB}\parallel \mathbf{DE}\]. Find \[\mathbf{a{}^\circ }+\mathbf{b{}^\circ }-\mathbf{c{}^\circ }.\]

A)  \[{{160}^{{}^\circ }}\]                                  

B)  \[{{120}^{{}^\circ }}\]

C)  \[{{180}^{{}^\circ }}\]     

D)  \[{{210}^{{}^\circ }}\]

Correct Answer: C

Solution :

(c): \[a+x={{180}^{{}^\circ }}\] \[c+x=b\Rightarrow x=b-c\] \[\therefore \]\[a+\left( b-c \right)={{180}^{{}^\circ }}\] \[\Rightarrow \]\[a+b-c={{180}^{{}^\circ }}\]