Side note: Please type the expression in here next time. Much preferable to an image hosted (temporarily) on another site...

I can't even understand what you're asking for. The image contains three rows, all of the form "DEF area X" where X is a mathematical expression. Is the first row supposed to be "DEF a = \frac{a^2}{4}\sqrt{3}"?

If so, these might be your lisp expressions.

- Code: Select all
`(defun area-1 (a)`

(/ (* a a (sqrt 3)

4))

(defun area-2 (a b)

(/ (* a b) 2))

(defun area-3 (a b c)

(let ((s (/ (+ a b c) 2)))

(sqrt (* s (- s a) (- s b) (- s c)))))

I have no idea how these show any useful attributes of a functional language or of lisp. They don't use first-class functions, macros, etc. Most people aren't drawn to the appearance of the consistent prefix notation; but many are sold on how it simplifies macros (functions that manipulate other code).