tolong jawabnya saya tk bisa dan tk ngerti a.b.c. bisa gk caranya!!plis

Kubus ABCD.EFGH

AB = 8 cm

BD² = AB² + AD²
BD = √(AB² + AD²)
BD = √(8² + 8²)
BD = √(2 . 8²)
BD = 8√2 cm

HB = √(AB² + AD² + DH²)
HB = √(8² + 8² + 8²)
HB = √(3 . 8²)
HB = 8√3 cm

EG = BD = diagonal sisi kubus
EP = 1/2 EG = 1/2 . 8√2 = 4√2 cm

AP = √(AE² + EP²)
AP = √(8² + (4√2)²)
AP = √(64 + 32)
AP = √(16 × 6)
AP = 4√6 cm