The question figure shows the 3D view of an object. Identify the most appropriate top view of the object from the given direction of the arrow.
Show Hint
Draw the plan: three vertical bands for the three treads; the notch in the high tread is closed by a riser on its right, while the notch in the middle tread opens into the lowest tread so the boundary line jogs.
Looking from above, the three treads (high, middle, low) appear as three vertical bands separated by two vertical lines (the risers). First notch: it is cut in the high tread at its near end, next to the riser. Its floor lies above the middle tread (a riser drops from the floor to the middle tread), so an edge remains between the notch and the middle band. In plan this is a small closed rectangle in the right part of the left band, with the band line continuing past it. Second notch: it is cut in the middle tread at its near end next to the low tread. Its floor is at the same level as the low tread, so there is no edge on its right side; the boundary between the middle and low bands steps left around the notch (the line goes down, turns left, then goes down again). Option (1) draws the second notch as a closed rectangle with the band line continuing, option (2) omits the first notch, option (3) omits both. Option (4) shows the closed first notch and the stepped boundary of the second notch. Answer: (4) the fourth drawing
