(20 14? As shown in the figure, in the quadrangular cone P-ABCD, the bottom ABCD is a diamond with a side length of 2, and ∠ DAB = 60. The side pad is a regular triangle.

(The full score of this small question is 14)

(1) proof: link BD.

Because ABCD is a prism and ∠ DAB = 60,

So △ABD is a regular triangle. (1 min)

G is the midpoint of AD, so BG is ⊥ ad. (2 points)

Plane PAD⊥ plane ABCD,

Plane PAD∩ plane ABCD=AD, (3 points)

∴BG⊥ airport (4 points)

(2) Solution: ∫△pad is a regular triangle, G is the midpoint of AD, ∴ PG ⊥ AD.

∵PG？ Plane pad, from (1): PG ⊥ GB. And from (1), BG ⊥ advertising.

∴PG, BG and AD are perpendicular to each other. (5 points)

Therefore, taking G as the origin, the spatial rectangular coordinate system G-xyz as shown in the figure is established.

PG = PD COS 30 = 3, GB = ABS IN 60 = 3, (6 points)

So G (0 0,0,0), D (0, 1 0), P (0 0,0,3), C (3 3,2,0), PD = (0, 1,? 3)，PC=(3，2，？ 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 has not been solved, please describe your problem in detail and provide free professional consultation through Baidu Law Professional Edition. Other similar questions 20 12-07-24. As shown in the figure, in the P-ABCD of a quadrangular pyramid, the bottom ABCD is a diamond with a side length of 2. The side pad is an equilateral triangle 92012-01-21. As shown in the figure, in the quadrangular cone P-ABCD, the bottom ABCD is a rhombus with a length of 2 ∠ DAB = 60, and the side pad is an equilateral triangle 1 120 12. The side pad is a regular triangle, perpendicular to the bottom ABCD. The bottom ABCD is a diamond with a side length of 2, ∠ bad = 60, and m is PC 1520 13-03-22. As shown in the figure, in the quadrangular cone P-ABCD, the bottom ABCD is ∠ dab = 60 and the side length is. As shown in the figure, the planar pad is perpendicular to the bottom surface 242017-11-25. In the quadrangular pyramid P-ABCD, the bottom ABCD is a diamond with side length A, and the side pad is a regular triangle with plane perpendicular to 142065438. In the quadrangular pyramid P-ABCD, the bottom ABCD is rhombic, and ∠ DAB = 60. The side pad is an equilateral triangle, with a flat PAD⊥ bottom ABCD, 20 14-03-08. In the quadrangular cone P-ABCD, the angle DAB of the bottom ABCD is 60, and the side length is long. Its 5820 10-08- 15 is shown in the figure. In the quadrilateral P-ABCD, the bottom ABCD is a diamond with a side length of A, and the side pad is a regular triangle, which is perpendicular to the bottom ABCD4. & gt recommended for you: F.context('cmsRight', [{'URL':'/d01373f082025aaf511aa256e9edab64034f1a07? 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 ':/builder/bjh-activity/articlesTask？ taskId = 1598082 & aside = 0 & footer = true & from = 0 '，' src ':'/203 FB 80 e 7 bec 54 e 773 ea 0680 ab 389 b 504 fc 26 a2d？ x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto '，' contractId ':' '，}，{ ' 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 ':' '，}])； The price of electric cars has dropped many times. Is the quality guaranteed? What impact will the "network toilet" have? Is Huaqiang North's second-hand mobile phone reliable? Why is the cost of cancer treatment getting higher and higher? 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 = 172068 1730；