find the surface area of a regular polygon inscribed in a pyramid in swift

main.swift
let n = 6 // number of sides of the polygon
let r = 5.0 // radius of the inscribed circle
let l = 10.0 // slant height of the pyramid

// Calculate the apothem of the polygon
let apothem = r * cos(.pi / Double(n))
// Calculate the perimeter of the polygon
let perimeter = 2.0 * r * sin(.pi / Double(n)) * Double(n)
// Calculate the area of the polygon
let polygonArea = 0.5 * apothem * perimeter * Double(n)
// Calculate the base area of the pyramid
let baseArea = pow(r, 2) * Double(n) * 0.5 / tan(.pi / Double(n))
// Calculate the lateral area of the pyramid
let lateralArea = perimeter * l * 0.5
// Calculate the total surface area of the pyramid
let surfaceArea = baseArea + lateralArea + polygonArea

print(surfaceArea)
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