Question 339135
Use the Pythagorean theorem,
{{{A^2+B^2=H^2}}}
{{{A^2+(A-6)^2=30^2}}}
{{{A^2+A^2-12A+36=900}}}
{{{2A^2-12A-864=0}}}
{{{A^2-6A-432=0}}}
{{{(A-24)(A+18)=0}}}
Only positive solutions make sense in this problem,
{{{A-24=0}}}
{{{highlight(A=24)}}}cm
{{{B=A-6=24-6=18}}}cm