If the length of the rafter includes the amount it overhangs the wall, saying the collar tie is at the midpoint of the rafter does not locate it with respect to the walls. Then the appropriate choice is ...
... D. not enough information
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If the midpoint of the rafter is taken to be the point halfway between the wall and the peak of the roof, then the midsegment postulate applies. The length of the collar tie is half the distance between the walls, hence ...
... A. 3.04 m
