area of a circle function file / prompt and fprintf() output

I have created a function file for the area of a circle, but I also need to include a prompt asking for the units of the radius. I also need to have the output area be expressed in the proper units, but am unsure of how to do either. This is what I have --

function [area] = area_circle(radius)
area = pi.*radius.^2;
end

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Bhaskar R]

function area_circle()
radius = input('Enter the radius: ');
area_cir = pi.*radius.^2;
disp(['Area of circle: ', num2str(area_cir)])
end