Exterior Angles Theorem is used.
The exterior angle of a triangle is equal to the 2 opposite interior angles.
Therefore, 65+78=143°, since 65 and 78 are the 2 opposite interior angles.
So, the answer is 143°
A1= 2520
a2= 14
a3= 9
a4= 20
b1= 6426
b2= 27
b3= 7
b4= h
b5= 34
C. is not a function since all the F9x) numbers are identical
