Question 109799

Solve for {{{a}}}

{{{c =  sqrt (a^2 + b^2)}}}..........raise both sides to the second power 

{{{c^2 =  (sqrt (a^2 + b^2))^2}}}..........

{{{c^2 =  a^2 + b^2}}}..........move {{{b^2}}} to the left

{{{c^2 - b^2=  a^2 }}}..........

or

{{{a^2 = c^2 - b^2 }}}..........


then:

{{{a = sqrt(c^2 - b^2)}}}