Answer:
13 ft.
Step-by-step explanation:
We can use the Pythagorean Theorem to solve this problem. The diagonals (lines from corner-to-corner) form the hypotenuses of two right triangles.
The Pythagorean states, a² + b² = c²; with a and b being the legs and c being the hypotenuse.
a = 12
b = 5
c = ?
12² + 5² = c²
144 + 25 = c²
169 = c²
√169 = √c²2
13 = c
c = 13
Here is a crude diagram showing what the room looks like with a diagonal:
Hope this helps!
