Hi Clark,

For the gable:

Click on the wall tool--> In the preview bar--> Click the wall style button--> the second icon is a gable. Select the pitch A and the pitch B to match the pitches of your roof. Define the height C as necessary. After you enter the pitch you need to press the enter key in your keyboard

For the ceiling

Draw the ceiling with the floor tool. Then:

Select the ceiling / object --> Edit--> Set object elevation--> write the desired elevation

or

Select the ceiling / object --> right click the elevation slider--> write the desired elevation

or

Select the ceiling / object--> right click on the piece--> Set elevation--> write the desired elevation

Hope this helps

Patricia