The two number lines are called the axes. A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line. The two number lines are called the axes.

The horizontal axis is called the x-axis. A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line. The horizontal axis is called the x-axis.

The vertical axis is called the y-axis. A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line. The vertical axis is called the y-axis.

The two axes divide the coordinate plane into four quadrants. A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line. The two axes divide the coordinate plane into four quadrants.

The point where the axes intersect is called the origin. A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line. The point where the axes intersect is called the origin.

Name the quadrant where each point is located. Check It Out: Example 1 Name the quadrant where each point is located. A. V B. Z C. T Quadrant I y-axis no quadrant Quadrant IV Helpful Hint Points on the axes are not in any quadrant.

An ordered pair gives the location of a point on a coordinate plane An ordered pair gives the location of a point on a coordinate plane. The first number tells how far to move right (positive) or left (negative) from the origin. The second number tells how far to move up (positive) or down (negative). The numbers in an ordered pair are called coordinates. The first number is called the x-coordinate. The second number is called the y-coordinate. The ordered pair for the origin is (0,0).

Example 2A Give the coordinates of each point. V From the origin, V is 4 units right and 2 units up. (4, 2)‏

Example 2B Give the coordinates of each point. Z From the origin, Z is 0 units right, and 4 units up. (0, 4)‏

Example 3: Graphing Points on a Coordinate Plane Graph each point on a coordinate plane. C. Z(0, 4)‏ D. T(1, –3)‏ x y 4 From the origin, move 4 units down. 2 –4 –2 0 2 4 From the origin, move 1 unit right, and 3 units down. –2 T –4 Z

Graph each point on a coordinate plane. C. P(1, –2)‏ Example 3A Graph each point on a coordinate plane. C. P(1, –2)‏ D. G(–4, –2)‏ x y From the origin, move 1 unit right and 2 units down. 4 2 –4 –2 0 2 4 From the origin, move 4 units left, and 2 units down. –2 G P –4

Additional Example 1: Drawing Polygons in the Coordinate Plane Graph the triangle with vertices F(2, 5), G(4, 1), and H(0, 22). Graph each point on the coordinate plane. Then connect the points with straight lines to form a polygon. 12

Lesson Quiz Part I 1. Graph the rectangle with vertices (2, 2), (2, 5 ), (-3, 5 ), and (-3, 2). 2 1 2 1