Linear program geometry

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I’ve tried to solve a question in my homework, and I don’t really know what to do. In the problem a polyhedron is given and I need to build the set of constraints that defines this polyhedron.

polyhedron

The faces of the Polyhedron are BCD, BCEO, BDFO, CDFE, EFO.

I never done that or seen an example. I have a "guess", I know that it's 3 dimension so it's probably a linear combination of three vectors, $x_1$, $x_2$, $x_3$ $(x,y,z)$, with other constraints.

\begin{align*} x_1+x_2+x_3&\leq3,\\ x_1&\leq1,\\ x_2&\leq2,\\ x_1,x_2,x_3&\geq0. \end{align*}

Am I right?

After that I need to find the set of vectors C that the face CDFE is the set of optimal solutions for the max problem define by this Polyhedron.

What exactly I need to do in the second part?

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Every plane, with equation $ax+by+cz+d=0$, divides all space into two parts (half-spaces) defined by $ax+by+cz+d>0$ and $ax+by+cz+d<0$. Your polyhedron is the intersection of five half-spaces, originating from its five faces.

For instance: faces $BCEO$ and $BDFO$ give two half spaces: $y>0$ and $x>0$. Proceed in the same way to find the other three constraints.

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Sorry it took me so much time to respond, I was working on another question. I thought about this question again. If we look we have two polyhedrons, AEOF and BGOH, and the polyhedron we need is the intersection between this two polyhedron. So I think this two equations describes our polyhedron:

4X+2Y+Z <= 4 and X+2Y+2Z <= 6

what do you think?