How to extrude a random direction spline, and dead halt face in SolidWorks

A simple example as the following image:

In this case, how to fully insert this hallow and contact with sided edge? So I will instruct SolidWorks self- studying learner using effectively “Extruded” command. To implement we do:

Step 1:  create a simple block as the above image

Step 2:  create Sketch on the bottom triangle Plane

Step 3: choose “Extruded Boss/Base” and implement as the following:

Click “Ok”   we have the result

So only using simply “Extruded Boss/Base” we controlled extruded direction as well as extrude Face of the block accurately without “Extruded Cut” or other complicated command