Expand menu menu_open Minimize Start chapters Home History history History expand_more
{{ item.displayTitle }}
navigate_next
No history yet!
Progress & Statistics equalizer Progress expand_more
Student
navigate_next
Teacher
navigate_next
{{ filterOption.label }}
{{ item.displayTitle }}
{{ item.subject.displayTitle }}
arrow_forward
No results
{{ searchError }}
search
menu_open
{{ courseTrack.displayTitle }}
{{ statistics.percent }}% Sign in to view progress
{{ printedBook.courseTrack.name }} {{ printedBook.name }}
search Use offline Tools apps
Login account_circle menu_open

Consecutive Interior Angles Theorem

Rule

Consecutive Interior Angles Theorem

If two parallel lines are cut by a transversal, the consecutive interior angles are supplementary angles.

In the figure above, 1\angle 1 and 4\angle 4 are supplementary as well as 2\angle 2 and 3.\angle 3. m1+m4=180m2+m3=180\begin{aligned} m\angle 1 + m\angle 4 = 180 ^\circ \\ m\angle 2 + m\angle 3 = 180 ^\circ \end{aligned}