Answer:
C. 54π + 20.25√3 cm²
Step-by-step explanation:
The shaded area can be split into two areas: a sector and an isosceles triangle.
Area of a sector is:
A = (θ/360°) πr²
where θ is the central angle and r is the radius.
Area of an isosceles triangle can be found with SAS formula:
A = ½ ab sin θ
where a and b are two sides of a triangle and θ is the angle between them.
In this case, r = a = b = 9 cm. The central angle of the sector is 240°, and the vertex angle of the triangle is 120°. Therefore, the total area is:
A = (240°/360°) π (9 cm)² + ½ (9 cm) (9 cm) sin 120°
A = 54π + 20.25√3 cm²
