As shown in the figure, in the triangle ABC, ab = AC, BF = CD, BD = CE, given the angle a = 40, calculate the degree of the angle EDF

As shown in the figure, in the triangle ABC, ab = AC, BF = CD, BD = CE, given the angle a = 40, calculate the degree of the angle EDF

Because AB = AC, angle B = angle C
BF = CD, BD = CE, so the triangle FBD congruent triangle DCE
So angle BFD = angle CDE
Because angle BFD + angle FDB + angle B = 180 degrees, angle FDB + angle FDE + angle EDC = 180 degrees
So angle FDE = angle B
Because angle a = 40 degrees, angle B = angle C
So angle B = 70 degrees, so angle FDE = 80 degrees

As shown in the figure, BD, CE are the height on the edge AC and ab of the triangle ABC, BF = AC, CG = AB, explore the relationship between Ag and AF

AG = AF and Ag ⊥ AF
The reasons are as follows: ① AF = AG,
∵ BD and CE are higher than ∵ ABC,
∴∠ACG+∠BAC=90°,∠FBA+∠BAC=90°,
∴∠ACG=∠FBA,
∵BF=AC,CG=AB,
∴△ACG≌△FBA,
∴AF=AG．
②AF⊥AG,
∵△ACG≌△FBA,
∴∠G=∠EAF,
∵CG⊥AB,
∴∠G+∠GAE=90°,
∴∠EAF+∠GAE=90°,
∴AG⊥AF,
⊥ Ag = AF and Ag ⊥ AF
That's right. If you don't understand,

In the pyramid P ABCD, the angle ABC = angle ACD = 90 degrees, angle BAC = angle CAD = 60 degrees, and PA ⊥ plane ABC In the pyramid P ABCD, the angle ABC = angle ACD = 90 degrees, angle BAC = angle CAD = 60 degrees, and PA ⊥ plane ABCD, e is the midpoint of PD, PA = 2Ab = 2 1. Verification, PC ⊥ AE 2. Verification, CE parallel plane PAB 3. Find the volume V of the triangular pyramid P ace Help!

(1) The ⊥ PA ⊥ AC ⊥ f ⊥ PA ⊥ AC ⊥ f ⊥ PA ⊥ AC ⊥ f ⊥ PA ⊥ AC ⊥ f ⊥ PA ⊥ f ⊥ AC ⊥ AC ⊥ f ⊥ AC ⊥ AC ⊥ f ⊥ AC ⊥ AC ⊥ AC ⊥ AC

In p-abcd, the angle ABC = angle ACD = 90 °, angle BAC = angle CAD = 60 °, PA ⊥ plane ABCD, e is the midpoint of PD, PA = 2Ab = 2, Prove (1) ce ∥ plane PAB (2) find the volume of triangular pyramid p-ace

1) It is proved that: take the midpoint m of AD, connect em, cm, then EM ∵ pa. ⊄ EM ⊄ plane PAB, PA ⊂ plane PAB, ∵ EM ⊂ plane PAB. In RT ⊄ ACD, ∵ CAD = 60 °, AC = am = 2, ∵ ACM = 60 °. While ∵ bac = 60 ⊄ plane PAB, ab ⊂ plane PAB, ⊂ MC ⊂ plane PAB, ⊂ MC ⊂ plane PAB, ⊂ MC ⊂ flat

In the tetrahedral ABCD, it is known that AC ⊥ BD, ∠ BAC = ∠ CAD = 45 ° and ∠ bad = 60 ° are known. It is proved that plane ABC ⊥ plane ACD

Be ⊥ AC, the perpendicular foot is e, and connect de. ∵ be ⊥ AC, BD ⊥ AC, be ∩ BD = B, ∩ AC ⊂ plane BDE, ⊂ AC ⊂ De, ⊂ DEB is the plane angle of the dihedral angle formed by plane ABC and plane ACD. Let de = a, ∵ CAD = ≁ BAC = 45 °, DEA = ∩ bea = 90 °, AE = be = a, ad =

If the quadrilateral ABCD is rhombic, ∠ ABC = 120 ° and ab = 12cm, then the degree of ∠ abd is_____ Can you help me with DAB's degree If the quadrilateral ABCD is rhombic, ∠ ABC = 120 ° and ab = 12cm, then the degree of ∠ abd is_____ The degree of DAB is______ ; diagonal BD=_______ ,AC=_______ The area of diamond ABCD is_______ I think the angle DAB is 60 degrees. Why is it wrong

60 degrees, 60 degrees, 12cm, 12 pieces, 2144 pieces, 2 pieces, you think is correct

As shown in the figure, it is known that circle O and circle O 'intersect at two points a and B, point O is on circle O', and chord OC of circle O 'intersects AB at point D. (1) verification: OA ^ 2 = OC * CD; (2) if a

Where is the picture!

As shown in the figure: AC= CB, D and E are the midpoint of radius OA and ob respectively, Confirmation: CD = CE

Proof: connect OC
In ⊙ o, ⊙ o, ∵
AC=
CB
∴∠AOC=∠BOC，
∵ OA = ob, D and E are the midpoint of radius OA and ob respectively,
∴OD=OE，
∵ OC = OC (common side),
∴△COD≌△COE（SAS），
The corresponding sides of an congruent triangle are equal

It is known that, as shown in the figure, AB is the diameter of ⊙ o, the chord CD is vertically bisected OA, and the perpendicular foot is point E. point F is the midpoint of arc CB, and the straight line passing through point F The straight lines AB and CD are located at points g and m, with mga = 30 ° and FG = 2 times the root 3 (1) verification: the line GM is tangent to ⊙ o (2) if h is a point on the arc BD, the intersecting diameter of chord FH is ab at point P, and COS angle BFH = 5 / 8, find the value of AP: PF

As shown in the figure, the chord ab of ⊙ o is perpendicular to the diameter CD, the perpendicular foot is f, and the point E is on AB, and EA = EC. As shown in the figure, the chord ab of ⊙ o is perpendicular to the diameter CD, the perpendicular foot is f, the point E is on AB, and EA = EC

As shown in the figure, in ⊙ o, C is If BC = 10 and Ce: EB = 3:2, find the length of ab

∵ BC = 10, and Ce: EB = 3:2,  CE = 6, be = 4, ∵ C is the midpoint of ACB, CD is the diameter, ∵ CD ⊥ AB, ∵ Pb = PA, ∵ BPC = 90 °, PE ⊥ BC, ∵ BEP = 90 °, ∵ EBP = ∵ PBC, ∵ BEP ∵ BPC, ∵ BP: BC = be: BP, that is PB2 = be · BC = 4 · 10, M Pb = 210, ∧ a