Exercise 27 Page 393

Practice makes perfect

a If three points are collinear, you can say that the middle point is between the other two points.

Since the points A, B, and C are on a straight line, and B is in the middle, the statement is true.

b Three points are collinear if all of them are on a straight line.

Point C is not on a straight line with B and E. Therefore, the statement is false.

c As we can see in the picture, the points A, D, and H are on a straight line.

Hence, they are collinear and we can say that point D lies between points A and E. The statement is true.

d If we look very closely, we can see that there is not a straight line between C, E, and F. The direction changes slightly between CE and EF.

Since the points are not collinear, we cannot say that E is between C and F. Therefore, the statement is false.

Communicate Your Answer p.387

Monitoring Progress p.388-391

Exercises p.392-394

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