The average length of the sides of triangle ABC is 12. What is the perimeter of triangle ABC?
Choose the correct choice from the following answers: A) 4 B) 6 C) 12 D) 24 E) 36
(average) = (perimeter)/3;   12 = (perimeter)/3;   (perimeter) = 36.   Answer: 36.
<result>E</result>
The average length of the sides of triangle ABC is 12. What is the perimeter of triangle ABC?