Exercise from SICP:

Exercise 1.2.

Define a function that takes three numbers as arguments and returns the sum of the two larger numbers.

Solution

The first thing we need to do is to get the largest two numbers from 3 numbers. We can do this with a conditional statement.

(define (sum-square-largest-two a b c)
        (cond ((and (<= a b) (<= a c)) (sum-of-squares b c))
              ((and (<= b a) (<= b c)) (sum-of-squares a c))
              ((and (<= c a) (<= c b)) (sum-of-squares a b))))