The height of the rhombus = 42 cm, it is 80% of the side of the rhombus. Find the area of a rhombus.

The area of the rhombus is calculated by the formula: S = a * h, where a is the side of the rhombus, h is the height of the rhombus.

In order to find out the length of the side, let’s make the proportion:

42cm = 80%;

a = 100%.

Calculate a by the “cross” rule:

42 * 100: 80 = 52.5 cm.

Find the area of the rhombus:

S = 52.5 * 42 = 2205 cm ^ 2.

Answer: the area of the rhombus is 2205 cm ^ 2.