43) What is the ventilator provided in continuation of Door/Window at its top?

44) Which window is provided on sloping roof?

45) What is the process of sinking the edge of one piece of timber to another by cutting grooves across its grains?

46) Which is used to subdivide a door or window with a vertical member of a frame?

47) What is a depression / recess inside the doorframe to receive the shutter?