4. (8 points) Count the number of triangles in the figure: $\qquad$ triangles.

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4. (8 points) Count the number of triangles in the figure: $\qquad$ triangles.

【Solution】Solution: 4 triangles made up of 1 piece;
2 triangles made up of 2 pieces;
2 triangles made up of 3 pieces;
Total: $4+2+2=8$ (triangles);
Answer: There are 8 triangles in the figure.
Therefore, the answer is: 8.