A triangle can be formed when the sum of the lengths of any two sides is greater than the length of the third side.
Practice makes perfect
We want to draw a polygon with side lengths of 25 millimeters, 36 millimeters, and 38 millimeters. We can recall that a triangle can be formed when the sum of the lengths of any two sides is greater than the length of the third side. Let's compare the side lengths using a table!
Comparison
25mm+36mm? >38mm
25mm+38mm? >36mm
36mm+38mm? >25mm
61mm > 38mm âś“
63mm > 36mm âś“
74mm > 25mm âś“
Notice that each sum of the lengths of any two sides is greater than the length of the third side. This means that we can draw a polygon with the given side lengths. Now we can use a ruler and compass to draw our triangle. First we can draw a 38-millimeter, or 3.8-centimeter side.
To find the position of the third vertex, we can open the compass to 36 millimeters. Then we can put the compass at one of the vertices and draw an arc.
Next, we will draw an arc with the compass open to 25 millimeters. Remember to put the compass at a different vertex than the 36-millimeter side.
The point of intersection is the location of the third vertex of the triangle. Finally, we can draw our triangle. We can do so by connecting the vertices with the segments.
