Answer:
140
Step-by-step explanation:
180 - 120 = 60 (angle3)
180-100 = 80 (angle 2)
180 - (60 + 80 ) = 40 (angle 1)
180- 40 = 140
answer b.
D corresponds to the base.
Ethire C or A corresponds to the height.
I'm sorry, that's all I know. I'm new to this kind of math.
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