Answer:
26.91 ft
Step-by-step explanation:
Well you can do this using the Pythagorean theorem and apply this to your room, which is a rectangle.
Diagonal = √h²+w²
where: h = height and w = width
So we insert our given:
Diagonal = √(20ft)²+(18)²
= √400ft² + 324ft²
= √724ft²
= 26.91ft
You can look below to see the scenario.