<PRE><B>Question 997774</B>
a+b+c= 30
a= 7
b=13
c= x 
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Now, in the equation above, substitute letters for known values:
7+13+x= 30 Add numbers on the left:
20+x= 30 Subtract 20 from both sides:
x= 10 This is the length of c. Your sides are:
a= 7; b= 13; c= 10</PRE>