gettotalarea.fsx

(*
    Finish this kata with the unit tests as your only help!

    Task:
    Implement:
    getTotalArea
    Define the different shapes: Square, Rectangle, Circle and Triangle

    taken from: https://www.codewars.com/kata/5702e2f380b8c86df3000003/train/fsharp
*)

type Shape =
|Triangle of baseline : float * height : float
|Square of side : float
|Rectangle of a : float * b : float
|Circle of radius : float

let getTotalArea shapes =
    shapes
    |> Seq.sumBy(function
                 |Triangle(baseline, height) -> 0.5 * (baseline * height)
                 |Square(side) -> side * side
                 |Rectangle(height, width) -> height * width
                 |Circle(radius) -> (pown radius 2) * System.Math.PI)
    |> (fun sum -> System.Math.Round(sum, 2))


// let triangleBase = 4.
// let height = 6.
// let triangle = Triangle(triangleBase, height)
// Assert.Equal("", 12.00, getTotalArea [triangle])

// Assert.Equal("", 49.14, getTotalArea [Rectangle(4., 2.); Rectangle(3., 4.); Circle(1.); Square(1.); Triangle(10., 5.)])