Method 1: ∵PA⊥ Aircraft ABCD∴PA⊥BC

The line AE: the bottom ABCD is a diamond ∠ ABC = 60.

∴△ABC is a regular triangle,

When there is East ∴BC⊥AE, it is the midpoint of BC.

And PA∩AE=ABC⊥ aircraft PAE∴BC⊥PE.

Method 2: Establish a rectangular coordinate system with AE, AD and AP as X, Y and Z axes respectively.

Prove BC by vector method? PE=0，

The conclusion is that BC⊥PE can also be used.

(2) From I, we know that AE, AD and AP are perpendicular to each other, so we establish a spatial rectangular coordinate system with AE, AD and AP as X, Y and Z axes respectively.

∵PA=AB=2∴A(0,0,0),B(3？ 1，0)，C(3， 1，0)，

D(0，2，0)，E(3，0，0)，F(0， 1， 1)，P(0，0，2)

∴AF=(0, 1, 1),CF=(？ 3,0, 1)

Let the normal vector of the plane FAC be u = (x, y, z),

What about you? AF=0u？ Cf = 0 and u = (3,? 3,3)

The normal vector of the plane ACD is v = (0 0,0,2),

Let the plane angle of dihedral angle F-AC-D be θ,

So cos θ = | u? v||u|？ | v | = I praised it and stepped on it. What is your evaluation of this answer? Put away comments//high quality or satisfaction or special types or recommended answers dottimewindow.iperformance & window.iperformance.mark ('c _ best',+newdate); Lawyer recommendation service: If your problem is not solved, please describe your problem in detail and provide free professional consultation through Baidu Legal Pro. Other similar problems 2016-12-01(2014? Shunyi District 1 model) As shown by the quadrangular cone P-ABCD, the bottom ABCD is rhombic, ∠ bad = 60, and the plane PAD⊥ plane ABCD, PA = PD = AD = 232017-12-/KLOC-. G is a point on PA. 320 16- 12-02 As shown in the figure, in a quadrilateral P-ABCD, the bottom ABCD is a diamond, ∠ bad = 60, AB = 2,182012-/kloc-0. As shown in the figure, in the quadrangular cone P-ABCD, the bottom ABCD is a right-angled trapezoid, adc, ∠ ADC = 90, flat PAD⊥ bottom ABCD 62016-12-01as shown in the figure, in the quadrangular cone P. As shown in the figure, in the quadrilateral P-ABCD, the plane PAC⊥ plane ABCD, and PA⊥AC, PA = AD = 2. The quadrilateral ABCD satisfies BC 42016-12-01(201658). Beijing) as shown in the figure, in the quadrangular cone P-ABCD, PA⊥ surface ABCD and bottom ABCD are rhombic, AB=2, ∠ bad = 60. (1) Verification: I recommend B3 for you, especially F.context('cmsRight'). [{ ' URL ':'/d 0 1373 f 082025 AAF 5 1 1aa 256 e 9 edab 64034 f 1a 07？ x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto '，' contractId':'A24KA00562 '，}，{ ' URL ':/s？ word = % E6 % AC % A7 % E6 % B4 % B2 % E6 % 9D % AF & sa = searchpromo _ ozb _ zhidao _ tuijian '，' src ':'/3 BF 33 a 87 e 950352 AAF 5 df 4954 143 fbf2b 2 1 18 b6b？ x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto '，' contractId ':' '，}])； Is Huaqiang North's second-hand mobile phone reliable? Why is the cost of cancer treatment getting higher and higher? What impact will the "network toilet" have? The price of electric cars has dropped many times. Is the quality guaranteed? I recommend f.context ('recbrand', [{"img": "\/86D6277F9E2F07083523F69DFB 24B 899A901F20d? x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto "，" url":"/hm.js？ 6859 ce 5a af 00 FB 00387 e 6434 E4 FCC 925 "； var s = document . getelementsbytagname(" script ")[0]； s.parentNode.insertBefore(hm，s)； })(); window . TT = 17 19875478；