MD5: 020d82877d2ab3bb6203732e1ef7d1f0
Link: http://aachan.sageru.org/browse.pl?md5=020d82877d2ab3bb6203732e1ef7d1f0
Tags: tanasinn





         
         |\  
  tanasinn→ |∴\←?
         |∴∵\
         ~ ̄ ̄ ̄
           ↑
          tanasinn

         |\  
  tanasinn→ |∴\←tanisige
         |∴∵\
         ~ ̄ ̄ ̄
           ↑
          tanasinn

         A
         |\  
       α→ |∴\   ∠ABC=θ
         |∴∵\
        B~ ̄ ̄ ̄ C
           ↑
           β

S = 1/2・α・β・tanasinθ= tanasin.