posted by Shane .
The diagonals of a rhombus are 320mm and 240mm in length.Find the angles of the rhombus.
Since the diagonals of a rhombus are perpendicular, you have four right triangles, with sides 120-160-200.
if the angles of the rhombus are A and B,
tan A/2 = 3/4
tan B/2 = 4/3
evaluate and double, done.