Answer:
A
Step-by-step explanation: 20 x 3.28 is 65.6 round it up its 66
In order to find the product of two complex numbers their magnitudes are multiplied and their arguments(measure of angles) are added up.
For z₁
Magnitude = 4
Argument = π/3
For z₂
Magnitude = 3
Argument = 2π/5
So, the product of z₁ and z₂ will be:
Area of the base is πr² where r is the radius. The volume of a cone is ⅓ πr²h where h is the height.
So the volume is ⅓ π×9×10=30 π=94.25 cu in approximately.