Answer:
72 units
Step-by-step explanation:
[tex]a^2 + b^2 = c^2[/tex]
[tex]b = \sqrt{c^2 - a^2}[/tex]
[tex]b = \sqrt{90^2 - 54^2}[/tex]
[tex]b = \sqrt{8100 - 2916 }[/tex]
[tex]b = \sqrt{5184}[/tex]
[tex]b = 72[/tex]
So, the missing leg is 72 units long.
