A S A   →   S A S   (A_i opposite S_i)
 

a1 = a2 = s3 =
 
  s1 = s2 = a3 =

area =

If you have to put a coefficient using some function symbol (for example 1/5, √2), put it in a numerical form (0.2, 1.414213562373095), for example using this

examples