Video Transcript
The two angles 𝐴𝑚𝐷 and 𝐵𝑚𝐶
are called what angles. Here, we look to introduce some
terminology. We say that given a pair of
intersecting lines, the angles which are opposite to one another form a pair of
vertically opposite angles. That means angle 𝐴𝑚𝐷, which is
this one, and 𝐵𝑚𝐶, which is this one, are vertically opposite to one another. Similarly, angle 𝐴𝑚𝐶, that’s
this one, and 𝐵𝑚𝐷, which is this one, are also vertically opposite to one
another. So, the phrase that goes in the
blank here is “vertically opposite.”
