here is the solution and tutorial hope you would like it....
Take a plane and draw a rectangle. Then, take another plane 100 mm above it. Then, take a point on the origin of the rectangle and draw four 3d lines connecting that point to the corners of the rectangle...see picture.
Use the boundary / boss feature and select the rectangle sketch. In the pic you will see a dialogue box near the sketch .... select normal to profile.
In the feature also select the point ... you will see in the preview. Click OK...
This is how a four sided pyramid is to be drawn.