Question 878684
b and h base and height.


{{{b=3+2h}}} and {{{2b+2h=60}}}.

Perimeter simplifies as {{{b+h=30}}}.
{{{(3+2h)+h=30}}}
.
{{{3h=27}}}
{{{highlight(h=9)}}}.....
and then {{{b=3+2h}}} from the description,
{{{b=3+2*9}}}
{{{highlight(b=21)}}}.