Handbook - Tutorial - Problems about building polygons

Build a regular pentagon



Build a line Line1, using Line,
and define a segment AB on the line itself, using Segment.
Describe two circles, using Circle with center point, centered in A and in B, respectively. They intersect in two points; C is the one above the segment AB.
Drow the perpendicular to AB passing on C; it intersects AB in a point 1; drow the perpendicular to AB passing on A. It intersects the circle centered in A in 2.
Build a circle centered in 1, with radius 1-2, using Circle with center point. It intersects the line in 3.
Build a circle centered in B, with radius B3, using Circle with center point. It intersects the circle centered in A in a point D and the perpendicular passing on C in a point E.
Build a circle centered in E, with radius ED, using Circle with center point. It intersects the circle centered in B in a point F.
Build five segments: AB, BF, FE, ED, DA, using Segment. ABFED is the desired regular pentagon.