Question -
Answer -
In the given ΔABC, 
and 
. We need to find 
.
Here,
are vertically oppositeangles. So, using the property, “vertically opposite angles are equal”, we get,
Further, BCD is a straight line. So, usinglinear pair property, we get,
Now, in ΔABC, using “the angle sum property”, we get,
Therefore,