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Printsmc
geometry intermediate
Problem
Figure is a trapezoid with , , , , and . The length of is
(A)
(B)
(C)
(D)
Solution
Drop perpendiculars from and to , thus forming a 30-60-90 right triangle, a 45-45-90 right triangle, and a rectangle, as shown in the diagram. Since is a rectangle, we have . Also, from the properties of 45-45-90 right triangles, we have . Again since is a rectangle, , too. From the properties of 30-60-90 right triangles, we have . Therefore, .
Final answer
D