C is the bisector of arc, the angle ABC = 30, AC = 0.5ab = r, CB = 3 0.5 * r, where 0 stands for power number and 0.5 stands for root number.

By AC=AE= 1/2BD.

AE=r，BD=2r，r=2

And BD⊥ aircraft ABC, BD⊥AB, BD⊥BC,

AE∨BD, then AE⊥ surface ABC, AE⊥AB,AE⊥AC.

Then △AEC is an isosceles right triangle with ce = 20.5r.

AF=0.5r

Ef = 5 0.5/2 * r radical 5r.

If m is in BD and EM is connected, then ABME is a rectangle with ed = 50.5r.

CD=7^0.5r

Ce 2+ed 2 = CD 2, then the angle CED=90, that is, DE⊥EC.

DF=(BF^2+BD^2)^0.5=2.5r

De 2+ef 2 = df 2, then △DEF is a straight triangle, ∠ def = 90,

DE⊥EF

From DE⊥ef de⊥ec to de⊥

2. The volume is calculated according to the volume added by three cubes.

1 starts to sell, and consists of three quadrangular pyramids. The height is ready-made and can be directly calculated.

They are the four pyramids of EACF, and the height of EA △ACF is the bottom.

They are the four pyramids of DEFC, and Degao △EFC is the bottom.

They are pyramid DBCF, where DB is higher and △BCF is the bottom.

v=v 1+v2+v3= 1/3*(r*s△afc+5^0.5r*s△efc+2r*s△bcf)

Where s △ ACB =1/2 * r * 30.5r = 30.5/2 * r 2 is the square root of the dichotomy of three R.

s△afc= 1/4*s△afc=3^0.5/8*r^2

S △ BCF = 3/4 * s △ AFC = 3 1.5/8 * R2 The square of three eighths of the root number three r is 31.5, which is three times the root number three.

Where △ACO is an equilateral triangle, that is, CF = 30.5/2 * r.

s△efc= 1/2*cf*ef= 15^0.5/8*r^2

v = 1/3 *(3 0.5/8 * R3+5 * 3 0.5/8 * R3+3 1.5/4 * R3)= 3 0.5/2 * R3 = 4。