2 edges of a rectangular parallelepiped extending from one vertex is equal to 3 and 4 cm.

2 edges of a rectangular parallelepiped extending from one vertex is equal to 3 and 4 cm. The surface area of this parallelepiped is 94 cm, find the third edge extending from the same vertex

There is a rectangle at the base of the parallelepiped, then Sosn = AB * AD = 3 * 4 = 12 cm2.

Determine the area of the lateral surface of the parallelepiped.

Side = Sпов – 2 * Sсн = 94 – 2 * 12 = 70 cm2.

Let’s calculate the perimeter of the base.

Ravsd = 2 * (AB + AD) = 2 * 7 = 14 cm.

Then S side = 70 = Ravsd * AA1.

AA1 = 70/14 = 5 cm.

Answer: The length of the third rib is 5 cm.