A) \[{{45}^{{}^\circ }}\]
B) \[{{90}^{{}^\circ }}\]
C) \[{{30}^{{}^\circ }}\]
D) \[{{60}^{{}^\circ }}\]
Correct Answer: B
Solution :
(b): \[AB=AC=AD\] \[\Rightarrow \]\[\angle ABC=\angle ACB={{35}^{{}^\circ }}\] \[\Rightarrow \]\[\angle BAC={{180}^{{}^\circ }}-{{70}^{{}^\circ }}={{110}^{{}^\circ }}\] \[\Rightarrow \]\[\angle ADC+\angle ACD={{110}^{{}^\circ }}\] \[\therefore \]\[\angle ACD=\frac{{{110}^{{}^\circ }}}{2}={{55}^{{}^\circ }}\] \[\therefore \] \[\angle BCD=\angle ACB+\angle ACD\] \[={{35}^{{}^\circ }}+{{55}^{{}^\circ }}={{90}^{{}^\circ }}\]You need to login to perform this action.
You will be redirected in
3 sec