Answer:
if the height is h and the base is 2b
then we have:
½(2bh)=60→2bh=120
b²+h²=13²=169
so
(b+h)²=b²+h²+2bh=120+169=289
(b-h)²=b²+h²-2bh=169-120=49
so
b+h=17
|b-h|=7
so b can be 12 and h can be 5
or b can be 5 and h can be 12
which means the base is either 24cm or 10cm
