$3.14\times \left [ {\left ( {8+1\times 2} \right )^{2}-{8}^{2}} \right ]\div 4+3.14\times {1}^{2}$
$=3.14\times \left [ {\left ( {8+2} \right )^{2}-64} \right ]\div 4+3.14\times 1$
$=3.14\times \left [ {{10}^{2}-64} \right ]\div 4+3.14$
$=3.14\times \left [ {100-64} \right ]\div 4+3.14$
$=3.14\times 36\div 4+3.14$
$=113.04\div 4+3.14$
$=28.26+3.14$
$=31.4\left ( {平方米} \right )$
答:绿化带的面积是$31.4$平方米.