Since the sum of angles in a triangle is 180°, it follows that;
[tex]\begin{gathered} 4x+3x+2x=180 \\ 9x=180 \\ \text{ Divide both sides of the equation by }9 \\ \frac{9x}{9}=\frac{180}{9} \\ x=20 \end{gathered}[/tex]
Since line segment AB is parallel to the line segment CD, it follows from the Corresponding angles theorem that:
[tex]\begin{gathered} \angle{B}=\angle{BCD} \\ \text{ Therefore:} \\ \angle{BCD}=4x \\ \text{ Substitute }x=20\text{ into the equation} \\ \angle{BCD}=4\times20=80 \end{gathered}[/tex]
Therefore, The req
