Does an angle need to be written as angle abc or can it be written as angle b?

<ABC and <B both refers to the same angle. Both ways of writing is correct.

Yes, angle  is made two line
A is one point on one  line. C is one point on another line.
If A or C not existed , Angle B  is not defined. 
then ' Angle B '  is the premise 'Angle ABC'

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)