Answer:
B.
Step-by-step explanation:
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>
The equation of a line that passes thruogh the point (x1,y1) and has a slope of m is
y-y1=m(x-x1)
so
passing through (a,b) and having slope of b is
y-b=b(x-a)