Availability, in the context of a computer system, refers to the ability of a user to access information or resources in a specified location and in the correct format.
Defined, the triangle proportionality theorem states that if you draw a line parallel to one of the sides of a triangle that also crosses the other two sides, then that line will divide the two sides in a proportional way.
The triangle inequality theorem states that any side of a triangle is always shorter than the sum of the other two sides. Try this Adjust the triangle by dragging the points A,B or C. Notice how the longest side is always shorter than the sum of the other two. In the figure above, drag the point C up towards the line AB. As it gets closer you can see that the line AB is always shorter than the sum of AC and BC.