cv2.rectangle(image, start_point, end_point, color, thickness)
cv2.rectangle(Face, (x, y), (x+w, y+h), (255, 255, 255), thickness)
x,y-----------x+w
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|
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y+h
and the rest cv2.rectangle() will draw for you.
#P.S the x and y are coordinates and the w and h are width and height