∴∠C？ DC= 180 -∠C？ Da? -∠ CDA = 180-45-45 = 90, that is, c? D⊥CD
∵A？ a、C？ C⊥ bottom ABC, top a? b？ c？
∴A？ A⊥AB,C？ C⊥BC,A？ A⊥A？ c？
∴C？ D=√2，BD=√3，BC？ =√5
From Pythagorean Theorem, we can know ∠C? Db = 90, which means c? D⊥BD
∴C？ D⊥ plane BCD
Aircraft BC? D goes through a straight line. C? D
Aircraft BC? D⊥ plane BCD (if one plane intersects with the perpendicular of another plane, the two planes are perpendicular to each other)
(2) Solution: Know the aircraft BC? D put the prism in ABC-a? b？ c？ Divided into four pyramids c? ﹣A？ b？ BD and b-c? Computer aided design
∵C？ C⊥ plane ABC
∴C？ C⊥BC
∫∠ACB = 90, that is, BC⊥CA.
∴bc⊥c plane? Computer aided design
∴ Four pyramids? The volume of CAD = (1+2) ×1× (1/2 )×1× (1/3) =1/2.
Pyramid c? -A？ b？ BD = volume of triangular prism ABC-A? b？ c？ -The volume of Pyramid b-c? The volume of CAD =/kloc-0 /×/kloc-0 /× (1/2) × 2-1/2.
= 1/2
Pyramid c? -A？ b？ The volume of BD: Pyramid b-c? The volume of CAD =1:1.
Answer: the ratio of the two parts is pyramid C? -A？ b？ The volume of BD and pyramid B-C? The volume ratio of CAD is1:1.