Answer:
180 cm2
Area of a polyhedron:
15(=base)x12(=height)
=180cm2
btw parallelogram is a 2D pic how you can come out a ''base'' and ''height''? It should be called a polyhedron. Your question is weird.
If so, your ''area of parallelogram'' is 15cm2 since your question is hecking  weird.
Btw it's 15cm2 not 15
Please check ur question b4 u ask
 
        
                    
             
        
        
        
We just need to get the perimeter of the backyard.
Whole rectangle: length = 7ft ; width = 5 ft
Perimeter = 2(7+5) = 2(12) = 24 ft
        
             
        
        
        
We have an arithmetic sequence with 
<span>a0 = 1st 3-digit number divisible by 13 </span>
<span>a0 = 104 </span>
<span>d = 13 (why?) </span>
<span>last term is largest divisible by 13 = 988 </span>
<span>how many terms? (988-104)/13 + 1 = 69 </span>
<span>S = 69/2(104+988) = 37674</span>