Answer:
Equation: [tex]6.3+5.6+8.4+x=27.4[/tex]
Side lenght: [tex]x=7.1[/tex]
Step-by-step explanation:
By definition, the perimeter of a polygon can be calculated by adding the lenghts of its sides.
Let be "x" the unknown side lenght of the given polygon.
In this case, you know that the perimeter of this polygon is:
[tex]Perimeter=27.4\ cm[/tex]
Knowing that the known sides lenghts are: [tex]6.3, 5.6[/tex] and [tex]8.4[/tex], you can write the following equation:
[tex]6.3+5.6+8.4+x=27.4[/tex]
Finally, you must solve for "x" in order to find the unknown side lenght.
Therefore, this is:
[tex]x=27.4-6.3-5.6-8.4\\\\x=7.1[/tex]
