Summary
Highlights
An activity uses a map of Rizal municipalities as a Cartesian plane. The video identifies the coordinates and quadrant for various towns like Taytay (-1,-1) in Quadrant 3, Rodriguez (1,3) in Quadrant 1, Morong (1,-2) in Quadrant 4, and Binangonan (0,-3) which lies on the y-axis.
The Cartesian plane is formed by two intersecting real number lines, one horizontal (x-axis) and one vertical (y-axis). It extends indefinitely in all directions and is named after French mathematician René Descartes. The plane is divided into four quadrants, numbered counterclockwise starting from the upper right. The intersection of the axes is called the origin (0,0).
Each point on the Cartesian plane is represented by an ordered pair (x, y), where x is the x-coordinate (abscissa) and y is the y-coordinate (ordinate). Movement to the right or up is positive, while movement to the left or down is negative. Quadrant 1 has (+, +) signs, Quadrant 2 has (-, +), Quadrant 3 has (-, -), and Quadrant 4 has (+, -).
The video demonstrates plotting points by starting at the origin. For example, point M (2,1) means moving 2 units right on the x-axis and 1 unit up on the y-axis. Points on the axes (e.g., A (-3,0) or T (0,-4)) stay on those axes and do not move along the other coordinate if it's zero.
Conversely, the video shows how to find the coordinates of a given point. By starting at the origin and counting units moved horizontally and vertically, one can determine the (x,y) coordinates. For example, point H (3,3) is found by moving 3 units right then 3 units up.
After plotting points (H, O, P, E) and connecting them to form a rectangle, the video calculates its area and perimeter. The length is found to be 6 units and the width 7 units. Using the formulas, the area is 42 square units (Length x Width) and the perimeter is 26 units (2L + 2W).
The video concludes with a GeoGebra demonstration. Points are plotted using their coordinates (e.g., (-4,-4), (0,4), (4,-4), (-5,1), (5,1)) and then connected with line segments to form a star shape, illustrating the practical use of coordinate systems in software.