Question 565683
Just do the same thing as you would normally do. When you square a square root of a number, it cancels out to just the number--if you square the square root of x, the result is x.
a = 5, b = ?, c = {{{sqrt(89)}}}
{{{a^2 + b^2 = c^2}}}
{{{5^2 + x^2 = sqrt(89)^2}}}
{{{25 + x^2 = 89}}}
{{{x^2 = 64}}}
{{{sqrt(x^2) = sqrt(64)}}}
x = 8
Therefore, b = 8.
Hope I helped! Good luck! =)