diff --git a/collects/teachpack/2htdp/scribblings/image-guide.scrbl b/collects/teachpack/2htdp/scribblings/image-guide.scrbl index 2000dee343..ba50e55880 100644 --- a/collects/teachpack/2htdp/scribblings/image-guide.scrbl +++ b/collects/teachpack/2htdp/scribblings/image-guide.scrbl @@ -62,33 +62,30 @@ Instead, we can use @racket[beside/align] to line up the two triangles along their bottoms instead of along the middles (which is what @racket[beside] does). -@image-interaction[(above (beside/align "bottom" - (triangle 40 "solid" "red") - (triangle 30 "solid" "red")) - (rectangle 70 40 "solid" "black"))] - +@image-interaction[ +(define victorian + (above (beside/align "bottom" + (triangle 40 "solid" "red") + (triangle 30 "solid" "red")) + (rectangle 70 40 "solid" "black"))) +victorian +] + To add a door to the house, we can overlay a brown @racket[rectangle], aligning it with the center bottom of the rest of the house. -@image-interaction[(overlay/align "center" "bottom" - (rectangle 15 25 "solid" "brown") - (above (beside/align "bottom" - (triangle 40 "solid" "red") - (triangle 30 "solid" "red")) - (rectangle 70 40 "solid" "black")))] +@image-interaction[ +(define door (rectangle 15 25 "solid" "brown")) +(overlay/align "center" "bottom" door victorian)] We can use a similar technique to put a doorknob on the door, but instead of overlaying the doorknob on the entire house, we can overlay it just on the door. -@image-interaction[(overlay/align "center" "bottom" - (overlay/align "right" "center" - (circle 3 "solid" "yellow") - (rectangle 15 25 "solid" "brown")) - (above (beside/align "bottom" - (triangle 40 "solid" "red") - (triangle 30 "solid" "red")) - (rectangle 70 40 "solid" "black")))] +@image-interaction[ +(define door-with-knob + (overlay/align "right" "center" (circle 3 "solid" "yellow") door)) +(overlay/align "center" "bottom" door-with-knob victorian)] @section{Recursive Image Functions}