Question 690846
The area of the right triangle is
{{{ A = (1/2)*b*h }}}
where {{{ b }}} is the base  and {{{ h }}}
is the height
given: {{{ h = 2b }}}
By substitution:
{{{ A = (1/2)*b*2b }}}
{{{ A = b^2 }}}
given: {{{ A = 25 }}} cm2
{{{ 25 = b^2 }}}
{{{ b = 5 }}}
The longest leg is {{{ 2b }}}, so
{{{ 2b = 10 }}}
The longest leg is 10 cm
check:
{{{ A = (1/2)*b*h }}}
{{{ A = (1/2)*5*10 }}}
{{{ A = 50/2 }}}
{{{ A = 25 }}}
OK