find the surface area of a cone in rust

To find the surface area of a cone, you need to calculate the area of the base and the area of the curved surface, and then add them together. In Rust, you can write a function that takes the radius and height of the cone as arguments and returns the surface area using the following formula:

main.rs
let radius = 5.0;
let height = 10.0;

fn surface_area_cone(radius: f64, height: f64) -> f64 {
    let slant_height = (radius.powi(2) + height.powi(2)).sqrt();
    let curved_surface_area = std::f64::consts::PI * radius * slant_height;
    let base_area = std::f64::consts::PI * radius.powi(2);
    let surface_area = curved_surface_area + base_area;
    return surface_area;
}

let surface_area = surface_area_cone(radius, height);
println!("The surface area of a cone with a radius of {} and height of {} is {}.", radius, height, surface_area);
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In this code, we first calculate the slant height of the cone using the Pythagorean theorem (slant_height = (radius.powi(2) + height.powi(2)).sqrt()), and then use it to calculate the area of the curved surface (curved_surface_area = std::f64::consts::PI * radius * slant_height). We also calculate the area of the base (base_area = std::f64::consts::PI * radius.powi(2)), and finally add the two areas together to get the total surface area of the cone (surface_area = curved_surface_area + base_area).

Note: std::f64::consts::PI is a constant value in Rust that represents the mathematical constant pi (3.141592653589793).