Introduction to Graphs-Notes

Class VIII Math
Notes for Introduction to Graphs
   Pictorial and graphical representation are easier of understand.
   Bar graphs and pie graphs are used for comparing categories and parts respectively.
   A histogram is a bar graph that shows data in intervals.
   A line graph displays data that change continuously over periods of time.
   A line graph being wholly an unbroken line is called a linear graph.
   For fixing a point the graph sheet we take two mutually perpendicular lines called axes.
   The horizontal line of the axes is called the x-axis and the vertical line is called the y-axis.
        The purpose of drawing a graph is to show numerical facts in usual form so that they can be understood quickly, easily and clearly. We also know that a bar graph is used to show a comparison among categories. A bar graph may consists of two or more parallel horizontal or vertical bars of equal width.
        A pie-graph is used to compare various parts of a whole using a circle. A histogram is a bar-graph that shows data in intervals. It has adjacent bars over the intervals as shown below.
        A line-graph is called a linear-graph and it displays data that changes continuously over periods of time.