Question

In the given figure, $CE||BA$. If $\angle BAC=70°$ and $\angle ECD=50°$, find $\angle ACB$.

Answer 1

Here, $AB\parallel EC$

$\therefore \angle BAC=\angle ACE={70}^{\circ }$ (alternate angles)

$\Rightarrow \angle BCA+\angle ACE+\angle ECD={180}^{\circ }$ [Angles on a straight line are supplementary]

$\Rightarrow \angle BCA={180}^{\circ }-{120}^{\circ }$

$\therefore \angle BCA={60}^{\circ }$