Question 155501
Area of triangle is given by {A = (bh)/2)}}}
{{{b = h + 5 }}}
{{{18 = ((h+5)*h)/2 }}}
{{{36 = h^2 + 5h}}}
{{{0 = h^2 + 5h - 36}}}
{{{0 = (h + 9)(h -4)}}}
h = 4 or -9
Since the height cannot be -9, it must be 4
Base = h+5 = 9

Check your answer. Does {{{18 = (9*4)/2}}}