For the formula shown, solve for the indicated variable. Are you familiar with the formula? What does it represent? 
S = πrl + πr² for l

• A. l = (S - πr²)/πr
• B. l = (S + πr²)/πr
• C. l = (S - πr)/πr²
• D. l = (S + πr)/πr²

Answer: (A)