This video explains how to calculate the angles of a rhombus when given one angle.
In order to complete this task one should keep in mind the following properties:
Opposite angles in a rhombus are congruent to each other.
The diagonals bisect opposite angles.
The diagonals are perpendicular - intersect to form 90 degree angles.
There are four right triangles whose angle sum is equal to 180 degrees.