Which formula would be used to find the measure of angle 1?

1/2(a° + b°).

1/2(a° – c°).

1/2(b° + c°).

1/2(a° – b°).

-Answer-
D. 1/2(a° – b°).

1/2(a° + b°).

1/2(a° – c°).

1/2(b° + c°).

1/2(a° – b°).

-Answer-

D. 1/2(a° – b°).

Step-by-step explanation:

the first one, all those points on the line just make a strait line.

the correct answer is 1: 2

step-by-step explanation:

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