geometry overlapping rectangles

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by Stuart@KaplanGMAT » Wed Feb 25, 2009 12:23 pm
Hi!

It's really hard to see which lines are "heavy" from the diagram, but based on the correct answer I'm assuming that it's everything except the lines surrounding the shaded region.

If each rectangle has a permiter of 12, that means that the sum of the two perimiters is 24.

If the only non-heavy shaded parts of the perimiters is the triangle enclosing the shaded region, then we simply subtract the perimiter of that triangle from the total perimiter to find the "heavy line" length.

So: 24 - 3 = 21.
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by earth@work » Wed Feb 25, 2009 12:38 pm
Thanks Stuart, the "heavy lines" had confused me.