3x+2(5x-3)=7
3x+10x-6=7
13x-6=7
13x=13
x=1
Non linear and increasing
If the drawing of your octagon (or whatever) has been separated into triangles, and one triangle's area<span> is labeled, then you do not need to know the apothem. Just take the </span>area<span> of that one triangle, and multiply by the number of sides in the original </span>polygon<span>.</span>
