This week in math 10 one of the things we learned was how to calculate the length of a line segment using the x and y coordinates on the graph. In this blog post I will focus on finding the length of diagonal line segments.

Example:

 

How to find the length of a line segment:

*Note: A  and B *

When looking at the diagonal line segment one could notice that the line segment makes up part of a right triangle (shown in red), in other words think of the diagonal line segment as the hypotenuse of a right triangle. One of the ways of finding the hypotenuse of a triangle is by using the Pythagorean theorem (  ). In some cases you can count how long both side a and b are but, if you are not able to then in order to find what  and  are equal to you can use the formula  in which a =  and b =  . you then square and add the values of  and  together to get .  The last step to finding the length of the line segment is to square root both  and its value. If the square root of  and  isn’t a whole number you may leave it as a radical unless the question asks you otherwise.