A $99$-graph has exactly $231$ triangles

Any strongly regular graph with parameters $(99,14,1,2)$ contains exactly $231$ triangles, where a triangle is a $3$-element clique.

Since $\lambda = 1$, every edge lies in exactly one triangle, and every triangle contains three edges, so the number of triangles is $693/3 = 231$; equivalently $99 \cdot 14 \cdot 1 / 6$. A hypothetical $99$-graph is therefore a partial linear space with $99$ points and $231$ lines of size $3$, each point on $7$ lines.