Answer:73
Step-by-step explanation:
 
        
             
        
        
        
Ur answer in attachment hope it helps you
 
        
        
        
Answer:
270 yds squared    
Step-by-step explanation:
You need to area of each of the shapes that make up the triangular prism. So, the side triangles, the back rectangle, the bottom rectangle and the top rectangle. 
Side triangle (1x): base*height/2
12*5/2
60/2
30 yds, 60 yds for both sides. 
Back rectangle: length*width
5*7
35 yds
Bottom Rectangle: length*width
7*12
84 yds
Top rectangle: length*width
7*13
91 yds. 
To get the final answer, you add the surface areas together to get the final amount of yards: 30+30+35+84+91= 270 yds squared. Hope this helps.