Fikile must tie a rope from one corner of a building to another to prevent access, as shown in the plan below. How long must the rope be?

The problem describes a rope tied diagonally across a corner, forming a right-angled triangle with sides of 6m and 8m. The length of the rope is the hypotenuse of this triangle. We will use the Pythagorean theorem.

The Pythagorean theorem states that for a right-angled triangle, $a^2 + b^2 = c^2$, where $a$ and $b$ are the lengths of the two shorter sides (legs), and $c$ is the length of the hypotenuse.
Given $a = 6$m and $b = 8$m, we need to find $c$.

The length of the rope must be $\text{10 m}$.