[racket] Question about images in racket

I am trying to draw a small house in Racket. It draws a house frm a triangle, square, and rectangle. So it consumes a number and draws the shapes, places, them, and forms a neat house. 

This is what I have so far

(overlay/align "center" "bottom" 
                
                  (triangle 40  "solid" "tan")
                  (rectangle 50 50  "solid" "blue")
                  (square 100   "solid" "red")))

I need to make the triangle (which is inside the rectangle) go on top of the square so it can look like a house. that's all I need to do.  this has been driving me nuts. What am I doing wrong?
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