Question

In the figure, lines $j$ and $k$ are parallel. Find the value of $\angle Q$.

• A. ${50}^o$
• B. ${55}^o$
• C. ${75}^o$
• D. ${130}^o$

Answer 1

The correct option is A ${50}^o$

As seen in the image, if we draw a line parallel to $j$ and $k$ passing through the vertex, so that $\angle Q$ gets split into two angles $s$ and $t$, such that $s^o+t^o=Q^o$

Now, $s^o+{150}^o={180}^o$ since they are interior angles.

Also, $t^o={20}^o$, since they are alternate angles.

$\therefore s^o+t^o={50}^o=Q$