Divide $13.80 by 4, then multiply by 6 to get $20.70
If it is a bunch of dots on a graph, then the answer will be the one that has two sets of dots on the same vertical line (the y axis). so if there are two dots right above and below eachother, that graph is the correct answer.
Step-by-step explanation:



The new matrix obtained from a given matrix by interchanging it's rows and columns is called the transposition of matrix. It is denoted by
. Again , Interchange it's rows and columns in order to find ' A '.

Now , LEFT HAND SIDE ( L.H.S )

Here, I refers to identity matrix. A diagonal matrix in which all the elements of leading diagonal are 1 ( unit ) is called unit or identity matrix.
⟼ 
⟼ 
⟼ 
⟼ 
⟼ 
⟼ 
⟼ 
⟼ 
RIGHT HAND SIDE ( R.H.S ) : 0
L.H.S = R.H.S [ Hence , proved ! ]
Hope I helped ! ♡
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A=(3.14)(12.5)^2
A=(3.14)(156.25)
A=490.625 ft squared