To determine the number of straight lines in the star figure, follow these steps:

1. Identify each straight line that forms part of the star. The star is typically composed of intersecting triangles and additional lines that connect the vertices.
2. Count each distinct line only once, even if they visually overlap or form part of multiple shapes.
3. For the given star figure:

• The star is composed of two intersecting triangles.
• Each triangle contributes 3 lines. Hence, the total from the triangles is 3 \times 2 = 6.
• In addition, there are intersecting lines forming the star pattern which may not be counted initially.
• Upon detailed inspection, these intersecting lines account for additional single lines.
• Therefore, the total number of distinct straight lines in the star is 9.

Examining each component and its contribution, the correct answer is 9 lines.

Hence, the correct answer is 9.