Final answer:
United inches in framing is the sum of the length and width of a frame. A 16 x 20 frame would have a total of 36 united inches.
Step-by-step explanation:
The term "united inches" is used in framing and refers to the total linear inches of a frame, which is calculated by adding together the length and width of the frame. To find the united inches for a frame size of 16 x 20, simply add the length (16 inches) to the width (20 inches).
16 inches (length) + 20 inches (width) = 36 united inches.
Therefore, the correct answer is b) 36.