package main

// Shape defines the base for shape functions
type Shape interface {
	Area() float64
	Perimeter() float64
}

type Square struct {
	Shape
	Arm float64
}

func (s *Square) Area() float64 {
	return s.Arm * s.Arm
}

func (s *Square) Perimeter() float64 {
	return s.Arm * 4
}

type Triangle struct {
	Shape
	Base   float64
	Height float64
}

func (t *Triangle) Area() float64 {
	return (t.Base * t.Height) / 2
}

func (t *Triangle) Perimeter() float64 {
	return 0.0 // I forgot how to do this from just base and height.
}

func main() {
	t := &Triangle{
		Base:   15,
		Height: 30,
	}

	myT := t.(Shape)
}