Simplify
28m^2n^4 \div 8m^3n^2

28/8 = (28÷4)/(8÷4) = 7/2;
m^2 / m^3 = (m^2÷m^2)/(m^3÷m^2) = 1/m;
n^4/n^2 = (n^4÷n^2)/(n^2÷n^2) = n^2;
Finally, we obtain 7n^2/2m ;

A=bxh3.2x1.8=5.76 centimeters square