Almost all investment institutions make use of the trendline analysis. How and why the trendlines work is subject to debate. This can be discussed at a later stage. However the fact remains that the trendlines do happen and with frequency.
Trendlines also occur with different angles . These angles can be steep or very gradual can move sideways or down. In next 45 minutes will give you an idea of how to draw trendlines and the significance of any trendline break.
Also the trendlines can be drawn in different time frames.
Below is an example of a simple trendline in ITC
Draw a trendline on the nifty chart in the daily time frame below. Draw as many as you can.
Draw a trendline on the nifty monthly chart below