(1)m^2*0.8=0.468 m=0.765(2)内心(3)原式=2-0.5-3=-1.5(4)原式=根号3-根号2+2-根号3+2根号2-2=根号2
包装箱的底面边长是 0.76m1.三角形的内心 2.=4.53.=根号3-根号2+2-根号3+2*根号2-2 =根号2