Step 01Select the two polygons. Select extrude, then normal.
Step 02Move the faces until it reaches a desired point.
Step 03Scale faces.
Step 04Undo multiple recent actions by pressing Ctrl+Alt+Z until all signs of extruding are gone. Select the two polygons again. Select extrude region, then normal. Notice the two polygons are not separate.
Step 05Select the bottom faces. Select extrude region, then normal. Now select previously extruded faces.
Step 06Select scale, then uniform.
Step 07Select faces.
Step 08Select flatten, then X.
Step 09Notice the faces are now parallel to the Z axis and the faces are perpendicular to the X axis.
Step 10Leave the faces selected. Press E to select edges.
Step 11Notice the edges of the faces are automatically selected.
Step 12Right Click and select cut.
Step 13Then select 2.
Step 14Each edge has been cut into two edges. The new vertices created are automatically selected.
Step 15Move upper vertices Y. Then move corresponding lower vertices on the Y axis.
Step 16Select vertices. Scale uniform. The use of scale in this way can save much time!
Step 17Do the same for the other side. The results should look similar.
Click to move on - Basic Techniques
Click to move on - Advanced Techniques