MathDB

Nair has puzzle pieces shaped like an equilateral triangle. She has pieces of two sizes: large and small. https://cdn.artofproblemsolving.com/attachments/a/1/aedfbfb2cb17bf816aa7daeb0d35f46a79b6e9.jpg Nair build triangular figures by following these rules:

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Figure

1

is made up of

4

small pieces, Figure

2

is made up of

2

large pieces and

8

small, Figure

3

6

large and

12

small, and so on.

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The central column must be made up exclusively of small parts.

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Outside the central column, only large pieces can be placed. https://cdn.artofproblemsolving.com/attachments/5/7/e7f6340de0e04d5b5979e72edd3f453f2ac8a5.jpg Following the pattern, how many pieces will Nair use to build Figure

20

Problem Statement