For the operation of image, the first thing you need to do is to import the image library.
The frequently used image functions are below.
(circle radius mode color)
(square side-len mode color)
(triangle side-length mode color)
(overlay i1 i2 is ...)
The images are all lined up on their centers.
(overlay/align x-place y-place i1 i2 is ...)
using x-place and y-place to determine where the images are lined up
(place-image image x y scene)
Places image onto scene with its center at the coordinates (x,y) and
crops the resulting image so that it has the same size as scene. The
coordinates are relative to the top-left of scene.