Question 1007770
Use the Pythagorean theorem,
Assuming {{{c}}} is the hypotenuse,
{{{a^2+b^2=c^2}}}
{{{b^2=c^2-a^2}}}
{{{b=sqrt(c^2-a^2)}}}
{{{b=sqrt(26^2-19^2)}}}
{{{b=sqrt(676-361)}}}
{{{b=sqrt(315)}}}
Assuming {{{c}}} is not the hypotenuse,
{{{a^2+c^2=b^2}}}
{{{b^2=19^2+26^2}}}
{{{b^2=1037}}}
{{{b=sqrt(1037)}}}