Respuesta :

calculista
we know that
surface area of the cone=pi*r²+pi*r*l
r=5 cm
l is the slant height

l²=12²+5²-----> l²=169--------> l=13 cm
surface area of the cone=pi*5²+pi*5*13----> [25*pi+65*pi]----> 90*pi cm²

the answer is
90*pi cm² or 282.6 cm²