Given the two lengths c and a and an angle (the marked angle in the figure), how can one construct a triangle ABC so that AB = c, BC = a and angle BAC is the given angle? If the distance a from B is marked off by a circle (the compass), if there is a point C there is in general also a point D on line AC so that BD = BC and thus triangle ABD also has AB = c, BD = a and angle BAD is the given angle.
Drag the point called "drag" to change the angle, or change one or both of the side lengths. Observe that for some SSA, there is no point C or D at all, for others there are the two triangles ABC and ABD, and in special cases C = D and there is only one triangle. (When does this happen?)
Page by James King, 10/2002.