•  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
r14 vs r15
......
2828
식을 풀면
2929
3030
[math(\displaystyle \begin{aligned} \dfrac{1}{4a^{2}}(a+b+c)(a+c-b)(a+b-c)(b+c-a) \end{aligned})],
31
31
[math(\displaystyle \begin{aligned} \dfrac{1}{4a^{2}}\cdot 2s \cdot 2(s-b)\cdot 2(s-c)\cdot 2(s-a) \end{aligned})],