Activity #8__the "Segment with a Given Length" tool

This activity is design to show you how the [b]Segment with a Given Length [/b]tool works. You will create 3 different side lengths for a triangle and then verify that the lengths are accurate. Lastly, move around the lengths until you have formed a right triangle. See below for directions.
Segment with a Given Length Tool
[br][br]DIRECTIONS:[br][br]1.  Using [b]LINE TOOLS[color=#274e13],[/color][/b] select the [b][color=#0000ff]Segment with given Length[/color][/b].  Enter a length of 3.​[br][br]2.  While the [b][color=#0000ff]Segment with given Length [/color][/b]tool is still active, create two more lines with lengths of 4 and 5.​[br]​​[br]3.  Using the [b]MEASURE TOOLS,[/b] select [b][color=#0000ff]Distance or Length[/color][/b] and follow the directions. Are the lines 3, 4, and 5? [br]​[br]4.   Using the [b]BASIC TOOLS,[/b] select the [b][color=#0000ff]Move[/color][/b] tool. Arrange the lengths, creating a right triangle.[br]
QUESTION
What are the conditions to form a triangle? Not all lines can be arranged to make a triangle

Information: Activity #8__the "Segment with a Given Length" tool