Answer:
773 or 278.5 (if it only wants the sides the pic shows)
Explanation:
13*5=65
65/2=32.5 (since it is a triangle you by 2)
12*9=108
108/2=54
15*20=300 (it is a square so you leave it)
you do it on the other sides that you can't see in the pic.
Add all the numbers together: 32.5+32.5+54+54+300+300 or 32.5(2)+56(2)+300(2)=773
Hope this helps!