## Sunday, 13 September 2009

### Graph | Length of line

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In graph plotting, something we need to know the length of a segment of the line plotted.

This may be for the distance to be travelled (like in a field trip).
Or it may be for checking the material to be used in building a slanted pole / support.

Let's take an example to illustrate.

From the plot, if we are to calculate the length of the line between the two red crosses, we can use the well-known Pythagoras' Theorem.

However, we need to know the co0ordinates for the crosses or markres first, to check their positions.
For the lower cross, we will have x1 = 2, and y1 = 3.
For the upper cross, x2 = 6 and y2 = 5.

This allows us to determine that the length in the x-axis direction is 6 - 2 = 4 units.

The length in the y-axis direction will be 5 - 3 = 2 units up.

Using then Pythagoras' Theorem, lenght of targetted line segment will be given as sqrt(42 + 22) = 4.472 units.

From graph and its application with other maths theorem, you can find answers easily.
It is the choosing of the appropriate maths tools that is is key to having a solution in a proper way.

Many a times, you may find answers or solutions through different techniques and methods. But the number of steps are more. But it is still correct.

It is through practice and gaining experience in maths problem-solving that helps you reach a level that let you handle maths with mental ease and confidence.

Everyone can achieve that. It is the attitude. Do not fear maths. It is just a tools to solve problems.

Maths is interesting! Love maths !

Cheers!   :D