Can 3 planes intersect at a single point?

Question

I know that three planes can intersect having a common straight line as intersection. But I have seen in some references that three planes intersect at single point.The three planes were represented by a triangle. What is equation of a triangle?

Thanks in advance.

Answer 1

The general equation for a plane is $ax+by+cz=d$ for constants $a,b,c,d.$

I can't comment on the specific example you saw; you may often see a triangle as a representation of a portion of a plane in a particular octant. But three planes can certainly intersect at a point: consider the three coordinate planes, $x=0,y=0,z=0$.

And if you want all possibilities: