Then area $A = \sqrts(s - a+1)(s - a)(s - a-1) = \sqrt \frac3a2 \cdot \left(\frac3a2 - a + 1\right) \cdot \left(\frac3a2 - a\right) \cdot \left(\frac3a2 - a - 1\right) $ - Appfinity Technologies