In the figure to the right, if point C is the center of the circle and DB = 7, what is the length of DE in triangle EDB?
(1) x = 60°
(2) DE || CA[/img]
(1) x = 60°
(2) DE || CA[/img]
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If x =60, then the triangle ACB is an equilateral triangle. Since we don't know the values of AE or any of the angles related to it Insufficient!(1) x = 60°
DE||CA Implies triangles BAC and BED are similiar because(2) DE || CA
Angle ABC = Angle EDB
Angle BAC = Angle BED (Corresponding angles are equal)
Angle BCA = Angle BDE (Corresponding angles are equal)
So, BC/BD = AC/DE
Radius/Diameter = Radius /DE
DE = Diameter = 7 units
Sufficient!
IMO B
