Площади фигур (8-9 класс)

r  a 2 S  2a 2d 2               Прямоугольник                                                                      Квадрат                                              Площади фигур R  ;                                                                 d 2 R  a 2  d 2                                                                                                                                    2 2 a b                                                          d S                                                                    ab d sin2  2  2 d 2 bh S  ab 1 2 S                                         S                                                           S              Параллелограмм                                                                 Ромб h 2 r                                                                              2 b 2 1 a 2 r dd 1 4 a 2 2 2  r d S                                                         а – сторона ромба  AB                                                                                                 sin AH 2 d  ;   ;   AH  HB                ;  S 2 ar 1                                                                                                                                                                            1dd sin 2                                          d 2 2 BH  AB ;  S  ah                                                                                                                  S  sin2a ;  S                                                                                       Треугольник                       1 dd 12 2 S                                                                                                                                                ah S  S  1 2 ab sin                                                                                                    S  cpbpapp )( )( (    )              r                 S ab ;  p  где  cba 1 2                   Трапеция                                                                Произвольный четырехугольник                                                               S  ;   abc 4 R    tg pr S S 2 2 a 2 ctg  ;   r  cba  2 ab  cba  1 2 1 a 2 32a 4 ba  2                                                 S  h                                                                   S                                                                                                   S S   hMN sin2 dd 1 2                                                                   если                                                       S  , где pr  dd 1 sin2 2 ca  db  то        dcba  p  2                                                                                                                     Если  +  =  +  =180 dd                                                                                                                      1                                                                                                                      S                                                                                                                               α γ β δ 2 bd ( )( ac  dpcpbpap )( )(    0 ) Подборка материала Бараненко И. В. Подборка материала Бараненко И. В.