find the surface area of a regular polygon circumscribed around a triangular prism in rust

main.rs
use std::io;

fn main() {
    let mut height = String::new();
    let mut base_length = String::new();
    let mut num_sides = String::new();

    println!("Enter the height of the triangle prism: ");
    io::stdin().read_line(&mut height).expect("Failed to read input.");

    println!("Enter the base length of the triangle prism: ");
    io::stdin().read_line(&mut base_length).expect("Failed to read input.");

    println!("Enter the number of sides of the polygon: ");
    io::stdin().read_line(&mut num_sides).expect("Failed to read input.");

    let height: f64 = height.trim().parse().expect("Invalid input.");
    let base_length: f64 = base_length.trim().parse().expect("Invalid input.");
    let num_sides: i32 = num_sides.trim().parse().expect("Invalid input.");
}
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main.rs
    let apothem: f64 = base_length / (2.0 * (num_sides as f64).tan() * std::f64::consts::PI / num_sides as f64);
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main.rs
    let side_area: f64 = base_length * height;
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main.rs
    let polygon_perimeter = base_length * num_sides as f64;
    let polygon_area = polygon_perimeter * apothem / 2.0;
    let triangle_area = 0.5 * base_length * height;
    let surface_area = polygon_area * 2.0 + triangle_area * 2.0;
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main.rs
    println!("The surface area of the regular polygon circumscribed around the triangular prism is {}.", surface_area);
}
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