Question 199738
So solve your question, you must first find out the formula for Pythagorean Theorem.
The formula for that is a^2+b^2=c^2.
A and B being the legs.(3,4)
C being the hypotenuse. (in your case 5)

So plug in the numbers into the formula and then solve.

3^2+4^2=c^2
9+16=c^2
25=c^2

the square root of  25 =  c^2
5=c
Therefore, you proved that the distance between those two walls are 5 feet

To check your answer just plug in the 5 into the formula.
3^2+4^2=25
9+16=25
25=25