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Hi Jennifer. There are analytical ways to solve the question, using trig identities. However, an easier geomoetric solution would be to create a right angle triangle and identify one angle as X and the other as 2X. See this diagram: So the sin X = a/h and the cos 2X = a/h. Thus sin X = cos 2X. Since all triangles have angles adding to 180 degrees, you can quickly solve for X in the equation 90 + X + 2X = 180. This may not be the ONLY angle however. What happens if X is negative? Cheers,  


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