# Line Chart/Bar Chart

In case of line charts bar charts, understanding the process of slope calculation between two consecutive periods/constituents/segments, can give us the highest or lowest percentage change in the whole chart.â€‹

Example

When does the highest percentage increase occur between any two years during the whole period?

Solution

Let us start by going through the slopes of different lines joining the two values.

(Slope is defined as the tangent of the angle formed by the line in an anti-clockwise direction with the X-axis.)

If we find out the angle at the place of slope, it will serve the purpose.

It can be seen in the above line chart that the angle between 2005 and 2006 is the highest. Hence, the maximum percentage increase occurs during 2005-2006.

(Slope is defined as the tangent of the angle formed by the line in an anti-clockwise direction with the X-axis.)

If we find out the angle at the place of slope, it will serve the purpose.

It can be seen in the above line chart that the angle between 2005 and 2006 is the highest. Hence, the maximum percentage increase occurs during 2005-2006.

Let us see this through a final example:

Example

What is to be done if the angle formed between the two different periods is almost the same?

Solution

In the line chart given above, the line between 2006-2007-2008 is almost straight; hence the slope is almost the same. But, as we can see, the base (or, denominator) is lower in 2005 than in 2006, hence, the percentage increase in 2005-2006 will be higher than 2006-2007.

Whatever we have discussed till now about line charts is true for bar charts as well.