평행선과 각의 크기 구하기

문제

오른쪽 그림에서 두 직선 $l$과 $m$이 평행할 때, $\angle x$의 크기는?

\begin{tikzpicture} \draw[line width=0.5pt] (-2,0) -- (3,0) node[right] {$l$}; \draw[line width=0.5pt] (-2,-2) -- (3,-2) node[right] {$m$}; \draw[line width=0.5pt] (0,1) -- (2.5,-3); % Transversal

\coordinate (A) at (intersection of -2,0--3,0 and 0,1--2.5,-3); \coordinate (B) at (intersection of -2,-2--3,-2 and 0,1--2.5,-3);

% Angle 130 degrees: Top-left exterior angle relative to line l and transversal \path (A) ++(-1,0) coordinate (AL); % Left of A on line l \path (A) ++(-0.5,0.5) coordinate (AU); % Up-left from A on transversal \pic [draw, angle radius=0.6cm, "$130^\circ$"] {angle = AL--A--AU};

% Angle x degrees: Bottom-right interior angle relative to line m and transversal \path (B) ++(1,0) coordinate (BR); % Right of B on line m \path (B) ++(0.5,-0.5) coordinate (BD); % Down-right from B on transversal \pic [draw, angle radius=0.6cm, "$x^\circ$"] {angle = BR--B--BD};

\end{tikzpicture}