Triangles BDC and ACD are coplanar and isosceles. If we have angle ABC = 72 degrees, what is angle BAC, in degrees?
+600 Th
The problem has 2 interpretations, one is EP's (which is ambiguous, BAC can be anything -- use trig ceva). The other is the above (intended) one.
$2\angle BAC+180-72=180\implies \angle BAC = 36$. Easy.
