96. If the side of a regular triangle is $a$, then Khotimella gives the formula for its area as $\frac{1}{3} a^{2}+\frac{1}{10} a^{2}$. Is this formula correct, and how large is the error (in percent) in determining the area of the triangle using this formula?

## Problem from the Chartres Manuscript.
96. If $a$ is the side of an equilateral triangle, then its area $\Delta=\frac{a^{2}}{4} \sqrt{3}$. If we equate this expression to the one given by Columella, we obtain that $\sqrt{3}=\frac{26}{15}$, or $3=3 \frac{1}{225}=3,00(4)$. The error is $\frac{4}{27} \%$.

The Chartres Manuscript (on parchment, stored in the library of the city of Chartres) of the 11th century contains several excerpts from the works of Roman land surveyors.