Răspuns :
[tex]A_{romb}= \frac{d_1 \cdot d_2}{2}= \frac{7 \cdot 6}{2}=21~(cm^2). [/tex]
Aria rombului= (diagonala 1* diagonala 2)/2
Aria= 6*7/2
Aria = 3*7
Aria= 21cm²