A rhombus has sides of length 12 cm and an angle of 72 degrees. Find its area.

Diagonals of rhombus are perpendicular

area is (1/2) * d1 * d2 where d1 and d2 are the diagonal lengths

draw the diagonals on your rhombus and you will see a 30-60-90 triangle and then figure

sides will be 6, 6√3. 12

so d1 is 2*6 = 12

and d2 is 2*6√3 = 12√3

and area = (1/2) * 12*12√3

= 72√3 square cm.