Problem 2 Naming Segments and Rays

1. What are the names of the segments in the figure below?

   

   The three segments are D E ¯ d e bar  or E D ¯ , E F ¯ e d bar , comma , e f bar  or F E ¯ , f e bar , comma  and D F ¯ d f bar  or F D ¯ . f d bar , .

2. What are the names of the rays in the figure?

   The four rays are D E → d e vector  or D F → , E D → , E F → , d f vector , comma , e d vector , comma , e f vector , comma  and F D → f d vector  or F E → . f e vector , .

   Plan

   How do you make sure you name all the rays?

   Each point on the line is an endpoint for a ray. At each point, follow the line both left and right to see if you can find a second point to name the ray.

3. Which of the rays in part (B) are opposite rays?

   The opposite rays are E D → e d vector  and E F → . e f vector , .

✓ Got It?

2. Reasoning E F → e f vector  and F E → f e vector  form a line. Are they opposite rays? Explain.

Take note Postulate 1-1

Through any two points there is exactly one line.

Line t passes through points A and B. Line t is the only line that passes through both points.

Take note Postulate 1-2

If two distinct lines intersect, then they intersect in exactly one point.

A E ↔ modified eh e with left right arrow above  and D B ↔ modified d b with left right arrow above  intersect in point C.