Insert Block - reusable Contents

Home tab > Block panel > Insert

Select More Options ...

Insert point: Specify Onscreen
Scale X:1.5

Insert in the top of the room

Repeat the command
Scale: Check the "Uniform Scale, X:2"
Rotation: 180

Insert the block at the bottom of the room

Repeat the command
Scale X:1
Rotation: Specify Onscreen

Snap to the corner of the wall to define the rotation angle