Ex: Manipulating by 3D Gizmo

3D Gizmo work with 2D and 3D objects

Move

Home tab > Selection panel > Move Gizmo

Select the box

Move gizmo show on  the box

Click on the grip and move the 3D gizmo to the bottom-right corner

Click on the Y axis (green) and snap to one of the corner of the wedge
The box move along Y axis and stop at the left face of the wedge

Click on the X axis (red) and snap to the corner of the wedge

Click on the Z axis (blue) and snap to the top corner

Click on the Y axis (green) and snap to the right corner of the wedge

Rotate

Home tab > Selection panel > Rotate Gizmo

Select the box

Hover cursor over the green circle, the Y axis (green) show on the box

Click on the green circle to confirm the axis
Move cursor and snap to the lower-right corner for the rotation angle

Repeat the same steps, move and rotate the cylider on the wedge 

Scale

Home tab > Selection panel > Scale Gizmo

Select the cylinder

Move the Scale gizmo to the base of the wedge
Click on one of the axis and snap to the midpoint of the right edge of the wedge

Cylinder scale on the wedge