Bonjour,
Pythagore:
DC=
BC² = BD² + DC²
BC² - BD² = DC
7,7² - 4² = 59,29 - 16 = 43, 29
√43,29 =>6,58cm
DC = 6,58 cm
AB?
AB² = AD² + BD²
AB² = 2,5² + 4² = 6,25 + 16 = 22,25
√22,25 = 4,72
AB = 4,72cm
ABC rectangle?
AC² = AB² + BC²
AC =
AC = 2,5 + 6,58 = 9,08
AB = 4,72
BC = 7,7
9,08² = 4,72² + 7,7²
82,4464
22,2784 + 59,29 = 82,074
82, 074 < 82,4464
donc ABC n'est pas rectangle
