Calculate Total Edge Length: Cube with 6.5 cm Sides

To solve this problem, we need to find the total length of all the edges of a cube where each edge measures 6.5 cm. A cube has 12 edges, and the length of each edge is identical.

We'll apply the formula for the sum of the lengths of the edges of a cube:

• Formula: Total edge length = $12 \times \text{edge length}$

Substitute the given edge length into the formula:

Total edge length = $12 \times 6.5$.

Now let's do the calculation:

Total edge length = $12 \times 6.5 = 78$.

Therefore, the sum of the lengths of the edges of the cube is $\mathbf{78}$ cm.

The correct choice from the given options is choice 4, which corresponds to the result of $78$.