Answer:
[tex]\sqrt{416}[/tex] ft
or about 20.396ft when rounded to the third decimal place
Step-by-step explanation:
(assuming the question is to find the ladder's length)
let "l" be the ladder's length
[tex]20^{2} + 4^{2} = l^{2}[/tex]
[tex]400 + 16 = l^{2} = 416[/tex]
[tex]l = \sqrt{416}[/tex] ft
