We need to use the Pythagorean Theorem. The formula:
[tex]a^{2} + b^{2} = c^{2} [/tex]
5^2=2^2+b^2
25=4+b^2
b^2=21
b=[tex] \sqrt{21} [/tex]
All you have to do now is to take the square root of 21.
You can find that out by using a calculator.
Hope this helps!
