Question 397279
A rhombus is a parallelogram with all 4 sides equal.
The diagonals intersect at right angles, and they bisect each other.
If you think of he rhombus as 2 triangles reflected about the 
7 cm diagonal, then the altitudes of these triangles are
12/2 = 6 cm long. The area of 1 of these triangles is 
(1/2)x7*6 = 21 cm2
Twice this area 2 x 21 = 42 cm2 is the area of the rhombus
Hope it's right