Respuesta :

cello10
use the Pythagorean theorem

the hypotenuse is the ladder which is 20 ft and the base is 12 ft thus 

a^2 + b^2 = c^2 

a^2 + 144 = 400 
a^2 = 256 
a = 16 

so its 16 ft
abbywellman
this is pretty easy just use the pythagorean theorem of a^2+b^2=c^2

20 is the hypotenuse
12 is the base
12^2+b^2=20^2
144+b^2=400
b^2=256
b=16

the ladder will reach 16 feet up the wall
hope this helps! :)