Answer:
47.2075 cm²
Step-by-step explanation:
Area of the sector = centre angle / 360⁰ × πr² (take π = 22/7)
Area of the sector = 129⁰/360⁰ × 22/7 × 8²
Area of the sector = 129⁰/360⁰ × 22/7 × 64
Area of the sector = 72.0762 cm²
Area of the triangle = 1/2 × ab × sin (centre angle), where a = b = 8cm.
Area of the triangle = 1/2 × 8× 8 × sin 129⁰
Area of the triangle = 8 × 4 × sin 129⁰
Area of the triangle = 32sin129⁰
Area of the triangle = 24.8687 cm²
Therefore,
Area of the shaded region = Area of the sector - Area of the triangle
Area of the shaded region = (72.0762 - 24.8687) cm²
Area of the shaded region = 47.2075 cm²