Solve by completing the square.

a.
{2, 6}
b.
{2, –6}
c.
{–2, 6}
d.
{–2, –6}

Triangles abc and dfg are given. find the lengths of all other sides of these triangles if: b ∠a≅∠d, ab·dg=ac·df, ac=7 cm, bc=15 cm, fg=20 cm, and df-ab=3 cm.