Lesson 2-3

Example 1  Name Points Using Ordered Pairs
Write the ordered pair that names point R.  Then name the quadrant in which the point is located.

  Start at the origin.
  Move left to find the x-coordinate of point R, which is –3.
  Move up to find the y-coordinate, which is 2.

So, point R is named by the ordered pair (–3, 2).  Point R is located in Quadrant II.

Example 2 Graph an Ordered Pair

Start at the origin. The x-coordinate is 4. So, move 4 units to the right. 

Graph and label point D at (4, –3).

Next, since the y-coordinate is -3, move 3 units down. Draw a dot and label D. 

Example 3  Real-World Example
GEOGRAPHY   The world map can be divided into a coordinate grid where (x, y) represents (degrees longitude, degrees latitude).  In what country is the point (60longitude, 50 latitude) located?

Start at the origin.  Move 60 right and then 50 up.  This point is located in Russia.

Example 4  Real-World Example
Name a continent that is located entirely in quadrant IV.

Quadrant IV is the lower right quadrant.  Australia is the only continent located entirely in Quadrant IV.