#### Answer

Because a line extends infinitely in two directions, the two arrowheads are used.

#### Work Step by Step

By definition, a line extends infinitely in both directions, so this makes sense.

Published by
Prentice Hall

ISBN 10:
0133281159

ISBN 13:
978-0-13328-115-6

Because a line extends infinitely in two directions, the two arrowheads are used.

By definition, a line extends infinitely in both directions, so this makes sense.

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