# Errata for Picturing Programs -- 14

Feb. 4, 2011

pp. 258-259: Formatting errors that caused overprinting. It should read:

Then we need to add those two squares:

```(define (distance-to-top-left the-point)
; the-point              a posn
; (posn-x the-point)     a number (x)
; (posn-y the-point)     a number (y)
; (* (posn-x the-point) (posn-x the-point))    a number (x2)
; (* (posn-y the-point) (posn-y the-point))    a number (y2)
; (+ (* (posn-x the-point) (posn-x the-point))
;    (* (posn-y the-point) (posn-y the-point))) a number (x2+y2)
...)
```

and finally square-root that, using `sqrt`:

```(define (distance-to-top-left the-point)
; the-point              a posn
; (posn-x the-point)     a number (x)
; (posn-y the-point)     a number (y)
; (* (posn-x the-point) (posn-x the-point))    a number (x2)
; (* (posn-y the-point) (posn-y the-point))    a number (y2)
; (+ (* (posn-x the-point) (posn-x the-point))
;    (* (posn-y the-point) (posn-y the-point))) a number (x2+y2)
(sqrt (+ (* (posn-x the-point) (posn-x the-point))
(* (posn-y the-point) (posn-y the-point))))
)
```