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2017 AMC 12B Question 15

AMC12 · 2017 AMC 12B

Question 15

Let $ABC$ be an equilateral triangle. Extend side $\overline{AB}$ beyond $B$ to a point $B'$ so that $BB' = 3 \cdot AB.$ Similarly, extend side $\overline{BC}$ beyond $C$ to a point $C'$ so that $CC' = 3 \cdot BC,$ and extend side $\overline{CA}$ beyond $A$ to a point $A'$ so that $AA' = 3 \cdot CA.$ What is the ratio of the area of $\triangle A'B'C'$ to the area of $\triangle ABC?$
  1. $9 : 1$
  2. $16 : 1$
  3. $25 : 1$
  4. $36 : 1$
  5. $37 : 1$