A classic example to construct the sequence of the square roots of the first integer numbers.
The Pharo sketch constructs a sequence of right triangles. The hypotenuses are the square roots.
| figure triangle | figure := DrGeoSketch new fullscreen. triangle := [:p1 :p2 :p3 :n | |s1 s2 s3 perp cercle p4 | s1 := figure segment: p1 to: p2. s2 := (figure segment: p2 to: p3) color: Color red. s3 := figure segment: p3 to: p1. perp := (figure perpendicular: s3 at: p3) hide. cercle := (figure circleCenter: p3 to: p2) hide. p4 := (figure altIntersectionOf: cercle and: perp) hide. n > 0 ifTrue: [triangle value: p1 value: p3 value: p4 value: n -1] ]. triangle value: 0@0 value: -1@0 value: -1@1 value: 50An animated variation of this sketch: