(20 12? A model in Qingpu District is shown in the figure: in the triangular pyramid P-ABC, PA⊥ bottom ABC, if the bottom ABC is a regular triangle with a side length of 2, PB is in contact with the b

(20 12? A model in Qingpu District is shown in the figure: in the triangular pyramid P-ABC, PA⊥ bottom ABC, if the bottom ABC is a regular triangle with a side length of 2, PB is in contact with the bottom ABC. (1) Because PA⊥ bottom ABC, the angle between PB and bottom ABC is π3.

So what? ∠PBA=π3

Because AB=2 and PA = 23.

VP？ ABC= 13S△ABC？ PA= 13？ 34? 4? 23=2

(2) Connect PM, take the midpoint of AB as n, connect MN, and then MN∑AC.

So ∠PMN is the angle between PM and AC?

Calculated: PN = 13, MN= 1, PM = 15.

cos∠PMN= 1+ 15？ 132 15 = I praised it and stepped on it. What's your comment on this answer? Put away your comments and recommend lawyer services: If your problem is not solved, please describe your problem in detail and provide free professional consultation through Baidu Legal Pro. Other similar problems 2011-10-04 In the triangular pyramid P-ABC, PA is perpendicular to the bottom ABC. If the bottom ABC is a regular triangle with a side length of 2, and the angle between PB and the bottom ABC is 60 degrees, then m is BC. As shown in the figure, in the quadrangular pyramid P-ABCD, the bottom ABCD is a parallelogram, n is the midpoint of PB, and in the triangular pyramid P-ABC, the plane where A, N and D intersect is PC122017-12-16, and the bottom △ABC is Then the radius of the circumscribed sphere of the triangular pyramid is () 420 14-04- 17. As shown in the figure, in the triangular pyramid P-ABC, the base ABC is a regular triangle with a side length of 4, PA=PC=2√3, and the side PAC is perpendicular to the base 1020 14-04-20. PA=PC=2√3, and the side PAC is perpendicular to the bottom 1 120 13-20. It is known that the bottom P-ABC of a triangular pyramid is a regular triangle with a side length of 2, and the bottom ABC and H of PA⊥ are the midpoint of PB 620 12-02-03 in the triangular pyramid. And PA is perpendicular to the bottom ABC. verify that PB is perpendicular to BC820 16-0 1-22. In the triangular pyramid P-ABC, it is known that the bottom ABC is a triangle with C as the right angle, PC is perpendicular to ABC, AC= 18, PC=6, BC6 and many other similar problems. & 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 ':' '，}])； 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? Is Huaqiang North's second-hand mobile phone reliable? 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 = 1720879374；