a figure having nine sides and angles. In a regular nonagon, or that the angles and sides of which are all equal, if each side be 1, its area will be $6 \cdot 1818242 = \frac{2}{3}$ of the tangent of $70^\circ$ to the radius 1.
a figure having nine sides and angles. In a regular nonagon, or that the angles and sides of which are all equal, if each side be 1, its area will be $6 \cdot 1818242 = \frac{2}{3}$ of the tangent of $70^\circ$ to the radius 1.