(1) Proof: ∵BC⊥ Party AA 1C 1C, A 1C? Surface AA 1C 1C, ∴ BC ⊥ a1c.

In △AA 1C, AC = 1, aa 1 = c 1c = 2, ∠ caa 1 = π 3,

A 1c2 = ac2+aa 12 from cosine theorem? 2AC？ aa 1 cos∠CAA 1 = 12+22？ 2× 1×2×cosπ3=3，

Therefore, a 1c = 3. Therefore, there are AC2+A 1C2=AA 12, so AC⊥A 1C, and AC∩BC=C, ∴A 1C⊥ plane ABC. ..

(2) As shown in the figure, take C as the origin of the spatial coordinate system, and the straight lines of CA, CA 1 and CB as the X, Y and Z axes respectively.

Then c (0 0,0,0), b (0 0,0, 1), a (1, 0), a1(0 (0,3,0),

From this, we can get: d (12,32,0), e (0 0,32,0) BD = (12), praised and trampled. What's your comment on 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 for other similar problems through Baidu Law Pro 20 13-07-063. As shown in the figure, in triangular prism ABC-a1b1c1,AA 1⊥ face ABC, AA 1=3, and d is the midpoint of AC. 1620110-30 as shown in the figure, the prism ABC-a1b1c1, AB ⊥. ∠ bcc1= 60182010-12 as shown in the figure, in the prism AB ⊥ BC-a/kloc-0. In the triangular prism ABC-a1B 1C1,AB=AC=5, BB 1=BC=6, and d and e are the midpoint of AA 1 and b1c, respectively (in the straight. A 1b 65438 prism ABC-a1b1c1d1,where the side BB 1C 1Cis is rhombic and the midpoint b1. In triangular prism ABC-a1b1c1,d and e are AB respectively; in triangular prism ABC-a1b10-27, bb/kloc-0. A 1A = AC = BC = 1。 A 1B = √ 2 (1) Proof: Plane A 1BC 18 is recommended to you: F.context('cmsRight') is especially recommended. [{ ' 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 ':' '，}])； 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 = 1720 1 12493；