Question 1030628
Draw this.
Area of rhombus is the half the product of the diagonals.
The sides are 5 cm, and each of those is a hypotenuse of the triangles made by the diagonals.
The sides of a right triangle with hypotenuse 5 are 3 and 4.
One diagonal is therefore 6 cm and the other 8 cm.  Half their product is 24 cm^2.
The area is bh=24 cm^2
The base is 5 cm, so the height is 4.8 cm.
The area is also a^2*sin A, and the half angle for a corner is tangent (3/4).  Double that angle, take the sine of it, and multiply by 25, and the answer is 24.