Step-by-step explanation:
here's your solution
==> by using Pythagoras theorem
==> base^2 = hypotenuse^2 - perpendicular^2
==> hypotenuse = 18 , perpendicular = 16
==> base^2 = 18^2 - 16^2
==> base^2 = 324 - 256
==> base^2 = 68
==> base = √68
==> base = 8.24
[tex]hope \: it \: helps[/tex]