BOOK IV.

PROP. I. PROB.

In a given circle to place a straight line, equal to a given straight line, not greater than the diameter of the circle.

F

A

PROP. II. PROB.

In a given circle to inscribe a triangle equiangular to a given triangle.

PROP. III. PROB.

About a given circle to describe a triangle equiangular to a given triangle.

To construct an isosceles triangle which shall have each angle at the base double of the vertical angle.

To describe an equilateral and equiangular pentagon about a given circle.

To inscribe a circle in a given equilateral and equiangular pentagon.

To describe a circle about a given equilateral and equiangular pentagon.