In a rectangular parallelepiped, the height is 4 cm. It is 40% of the length and 80%

In a rectangular parallelepiped, the height is 4 cm. It is 40% of the length and 80% of the width. Find the sum of the areas of all the faces of the box.

Let us denote the height of the parallelepiped through c = 4 cm, the length – a cm, and the width – b cm.
40% = 0.4
a = 4 / 0.4 = 40/4 = 10 (cm)
80% = 0.8
b = 4 / 0.8 = 40/8 = 5 (cm)
S = 2 * (a * b + a * c + b * c) = 2 * (4 * 10 + 4 * 5 + 5 * 10) = 2 * (40 + 20 + 50) = 220 (sq. Cm)
Answer. The sum of the areas of all faces is 220 sq. cm.