ABCD is a rectangle, ∴AB∥CD, ∴EF∥CD,
∵EF leveling VCD, FG? Plane VCD
∴EF∥ plane VCD, fg∑ plane VCD,
And EF∩FG=F, ∴ plane efg plane VCD ... (4 points)
(ii) Method 1:
∵VA⊥ Aircraft ABCD, CD⊥AD, CD ⊥ VD.
Then ∠VDA is the plane angle of dihedral angle V-DC-A, and ∠ VDA = 30.
Similarly ∠ VBA = 45 ... (7 points)
For AH⊥VD, the vertical foot is H. From above, we can see that CD⊥ plane VAD, and then AH⊥ plane VCD. ..
∫ab∑ plane VCD, ∴AH is the distance from B to plane VCD.
According to (i), the angle formed by plane EFG∑ plane VCD, straight line VB and plane EFG is equal to the angle formed by straight line VB and plane VCD, and this angle is recorded as θ.
AH = VA？ sin60 =32VA
VB=2VA
∴ sin θ = ahvb = 64...( 1 1)
So the angle arcsin64 formed by the straight line VB and the plane EFG? ... (12 points)
Method 2:
∵VA⊥ Aircraft ABCD, CD⊥AD, CD ⊥ VD.
Then ∠VDA is the plane angle of dihedral angle V-DC-A, and ∠ VDA = 30.
Similarly ∠ VBA = 45 ... (7 points)
Establish the spatial rectangular coordinate system A-xyz as shown in the figure, let VA=VB= 1, BC=3,
So V (0, 0, 1), B (0, 1, 0), D (3, 0, 0), C (praised and trampled) 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 has not been solved, please describe your problem in detail and provide free professional consultation through Baidu Law Professional Edition. Other similar problems 2011-08-12. As shown in the figure, the V-ABCD bottom of the quadrangular pyramid is rectangular, the side VAB is perpendicular to the bottom ABCD, and VB is perpendicular to the plane VAD. Confirm that the plane VAC is perpendicular to the plane VBC3220 12-05- 13. In the quadrangular cone P-ABCD, the bottom ABCD is rectangular, and the side PA⊥ plane ABCD, AB= root number 32420 12-08-03 is shown in the quadrangular cone P-ABCD, and the bottom ABCD. In the pyramid V-ABC, VO⊥ plane ABC, O ∈ CD, VA = VB, AD = BD 2352010-1-15, and the quadrangular prism ABCD-a/kloc is known. Find the volume of the triangular pyramid C 1-ABF 2020-05- 14 in the quadrangular pyramid P-ABCD, the bottom ABCD is rectangular, and the PA⊥ plane ABCD 2017-/kloc-0-05 (20/kloc-0) As shown in the figure, in the quadrangular cone P-ABCD, the bottom ABCD is a parallelogram, PA⊥ bottom ABCD, BD⊥PC and E are the midpoint of PA 82020-05-05 as shown in the figure, and in the quadrangular cone V-ABC, VO⊥ plane ABC, O ∈ CD, VA =. [{ ' 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 = 1720 136857；