Answer: 8.58 cm²
Explanation:
The area of the central triangle bounded by each of the sides can be computed as ...
A = (1/2)r²sin(α) . . . . where α is the central angle, 360°/5 = 72°
There are 5 such triangles, so the area of the pentagon is
A = (5/2)(1.9 cm)²sin(72°) ≈ 8.58 cm²