Answer:
1. If it is just a line and it has no end points then it means that it is a line if it has endpoints then it's a line segnment.
2. a suplementary angle is equal to 180 degrees and congruent angels are equal angles. (conruent is just a fancy word for equal.)
Step-by-step explanation:
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Answer:
6.45
Step-by-step explanation:
6.9-6.0=0.9
0.9÷2=0.45+6=6.45
This is the middle between 18 and 21.
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