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Hello.
00:01
So here's a rough sketch of the given figure.
00:04
Now, from the figure here, we see that angle abc is equal to one half of ac.
00:10
So we have that angle abc is equal to one half of ac.
00:19
So therefore, abc is equal to one half times 80 degrees, which is equal to 40 degrees.
00:30
So this.
00:31
Therefore, we have that, well, a, b, c is equal to 40 degrees.
00:35
Now we consider triangle a, b, c, so we have that angle bac plus acb plus a, b, c, is equal to 180...