解;外套的面积:(5.6×3.5+1.2×5.6)×2, =(19.6+6.72)×2, =26.32×2, =52.64(平方厘米); 内盒的面积:(5.6×1.2+3.5×1.2)×2+5.6×3.5, =(6.72+4.2)×2+19.6, =10.92+19.6, =30.52(平方厘米); 答;内盒和外套所用硬纸的面积各是30.52平方厘米和52.64平方厘米. |
解;外套的面积:(5.6×3.5+1.2×5.6)×2, =(19.6+6.72)×2, =26.32×2, =52.64(平方厘米); 内盒的面积:(5.6×1.2+3.5×1.2)×2+5.6×3.5, =(6.72+4.2)×2+19.6, =10.92+19.6, =30.52(平方厘米); 答;内盒和外套所用硬纸的面积各是30.52平方厘米和52.64平方厘米. |