Proposition 4.1 Into a given circle to fit a straight line equal to a given straight line which is not greater than the diameter of the circle.
Proposition 4.10 To construct an isosceles triangle having each of the angles at the base double of the remaining one.
Proposition 4.14 About a given pentagon, which is equilateral and equiangular, to circumscribe a circle.
Proposition 4.16 In a given circle to inscribe a fifteen-angled figure which shall be both equilateral and equiangular.