The area of the rhombus with the side 30 and the radius of the inscribed circle 13 equal to 780
where a is the side, h is the height.
where d1,d2 are the diagonals.
where d is the diagonal, α° is the opposite angle in degrees.
where d is diagonal, α° - the included angle in degrees.
where r is the radius of the inscribed circle, α° is the angle between the parties in degrees.
A rhombus is a parallelogram with all sides equal.
Rhombus area formula 
where r is the radius of the inscribed circle,the a - side.
where a is the side, α° is the angle between the sides in degrees.Solution:
S = 2·a·r
=2·30·13
=
780
a: The area of the rhombus with the side 30 and the radius of the inscribed circle 13 equal to 780