LESSON FOURTH.
REVIEW.
Read all the vertical lines. (Diagram [4].)
Why is q r a vertical line?
What is a vertical line?
Read all the horizontal lines.
Why is 5 6 a horizontal line?
Define a horizontal line.
Read all the oblique lines.
Why is s t an oblique line.
What is an oblique line?
Note.—Lines that point in the same direction do not approach the same point.
Diagram 4.
Diagram 5.