Sum of squares of two largest (buggy)

#lang racket
(require htdp/testing)

(define (sum-of-squares-of-two-largest a b c)
  (define (sum-square x y)
    (+ (* x x) (* y y)) )
  (cond ((and (< a b) (< a c))
         (sum-square b c))
        ((and (< b c) (< b a))
         (sum-square a c))
        (else (sum-square a b) ) ) )

;; all different numbers
(check-expect (sum-of-squares-of-two-largest 1 2 3) 13)

;; small pair in all locations
(check-expect (sum-of-squares-of-two-largest 2 2 3) 13)
(check-expect (sum-of-squares-of-two-largest 2 3 2) 13)
(check-expect (sum-of-squares-of-two-largest 3 2 2) 13)

;; large pair in all locations
(check-expect (sum-of-squares-of-two-largest 2 3 3) 18)
(check-expect (sum-of-squares-of-two-largest 3 2 3) 18)
(check-expect (sum-of-squares-of-two-largest 3 3 2) 18)

;; all same numbers
(check-expect (sum-of-squares-of-two-largest 2 2 2) 8)

(generate-report)