In a large warehouse that smells of freshly cut wood in north Denver, 20 adults — including a refugee family from Somalia, a math teacher and a laid-off retail worker — gather in the unfinished frame of a house to take notes on the Pythagorean theorem. They are hoping that the equation, along with other basic measuring principles, will help them find work at the end of an eight-week construction course. “When the market crashed in 2008, a lot of people were forced to do something else.