1. **State the problem:** We have a sequence of patterns where each pattern number $n$ contains $n$ hexagons and $n$ triangles. 2. **Identify the pattern:** For pattern number 1, there is 1 hexagon and 1 triangle. For pattern number 2, there are 2 hexagons and 2 triangles. For pattern number 3, there are 3 hexagons and 3 triangles. 3. **General formula:** The number of triangles in pattern number $n$ is simply $n$ because the number of triangles equals the pattern number. 4. **Apply the formula:** For pattern number 90, the number of triangles is $$\text{Number of triangles} = 90$$ 5. **Conclusion:** There are 90 triangles in pattern number 90.