EconGirl wrote:

so kavincan, you are saying it's 42?

it does not make sense to me because if quadrilateral is to share only one side with the polygon than we'd need to draw 3 lines. But we can only draw 1 or 2 lines?

I must be missing something.....

The work so far is on the right track, but the answer is not 42. When they say one side, they should be thinking about

two non-adjacent sides. But there is a mistake in their reasoning. Can you find and fix it? Also, can you use the first reply to come up with an elegant solution?