The length of all the edges of the rectangle is 96 cm, its two dimensions are 7cm and 12cm. Find the third dimension.

Given:
The total length of all the edges of the rectangular parallelepiped is 96 cm.
The length of one rib is 7 centimeters.
The second rib is 12 centimeters long.

There are 4 of each rib in this figure.
Find the length of all edges of the first extension:
7 * 4 = 28 cm.
Let’s calculate how many centimeters are the second four edges:
12 * 4 = 48 cm.
Let’s find the length of the third type of ribs:
96 – 28 – 48 = 20 cm.
Let’s calculate what the length of the third dimension is equal to:
20: 4 = 5 itself.
Answer: 5 centimeters.