Answer: each guest gets 4.19 cm²
Step-by-step explanation:
The cake is a circle. The area which he cuts for himself is a sector with a central angle of 120 degrees. The formula for determining the area of a sector is expressed as
Area of sector = θ/360 × πr²
Where
θ represents the central angle
π is a constant whose value is 3.14
r represents the radius of the circle.
From the diagram,
r = 4cm
Therefore, area of the cake that he cut for himself is
120/360 × 3.14 × 4²
= 16.75 cm²
The total area of the cake is
3.14 × 4² = 50.24 cm²
Therefore, the rest of the cake is
50.24 - 16.75 = 33.49 cm²
The amount that each guest gets would be
33.49/8 = 4.19 cm²