2007 AMC 12B Problems/Problem 11
The angles in a quadrilateral add up to 360, regardless of what shape or size the figure takes. Let x be <A, so then: <B=.5x <C=(1/3)x <D=(1/4)x <A+<B+<C+<D=360 x+.5x+(1/3)x+(1/4)x=360 (25/12)x=360 x=172.8 or x is around 173, choice D.