please help do this math due in 2 hours ;-; i aint know how to do it, ill give you brain list or something like idc i just need this done

Assuming "A= bh 2 12/13/5 "
means
given Area=A=bh/2, and
the triangle has sides 5, 12 and 13.
(see diagram attached).

Since (5,12,13) for a Pythagoras triplet, it is a right triangle. 
(13^2=12^2+5^2 => 169=144+25)
The two legs are 5 and 12, respectively b & h.
So the area of the triangle is bh/2=5*12/2=30
If the measures are in metres, then the area is 30 m^2.