Add the racket file used in the second lab. Add content to second lab post

L02/hello.rkt

@@ -0,0 +1,22 @@
+#lang slideshow
+(define c (circle 10))
+(define r (rectangle 10 20))
+
+(define (square n)
+  (filled-rectangle n n))
+
+(define (four p)
+  (define two-p (hc-append p p))
+  (vc-append two-p two-p))
+
+(define (checker p1 p2)
+  (let ([p12 (hc-append p1 p2)]
+        [p21 (hc-append p2 p1)])
+    (vc-append p12 p21)))
+
+(define (checkerboard p)
+  (let* ([rp (colorize p "red")]
+         [bp (colorize p "black")]
+         [c (checker rp bp)]
+         [c4 (four c)])
+    (four c4)))

L02/hello.rkt~

@@ -0,0 +1,2 @@
+#lang racket
+(displayln "hello world")