As shown in the figure, be is the diameter of circumscribed circle O of △ ABC, CD is the height of △ ABC, and the proof is: AC · BC = be · CD

As shown in the figure, be is the diameter of circumscribed circle O of △ ABC, CD is the height of △ ABC, and the proof is: AC · BC = be · CD

It is proved that: connecting EC, ∵ BC = BC, ∵ e = a, and ∵ be is the diameter of ⊙ o, ∵ BCE = 90 °, and ∵ CD ⊥ AB, ∵ ADC = 90 °, and ∵ ADC ∽ ECB, ∵ aceb = cdbc, that is, AC · BC = be · CD

⊙ o is the circumscribed circle of △ ABC, the radius of ⊙ o is 6, ∠ ACB = 45 ° and the length of AB is calculated

Connecting AO and Bo, ∵ ∠ ACB = 45 °, ∵ AOB = 90 °, ∵ AB = 62 + 62 = 62

As shown in the figure, ⊙ o is the circumscribed circle of equilateral triangle ABC, and the radius of⊙ o is 2, then the side length of equilateral triangle ABC is ()
A. 3B. 5C. 23D. 25

Connect OA and make OD ⊥ AB to D, then ∠ oad = 30 °, OA = 2, ｜ ad = OA · cos 30 ° = 3, ｜ AB = 23

In a right triangle, the two right sides are 6cm and 8cm respectively, and the length of the hypotenuse is 10cm. If one side is rotated one circle respectively, what is the relationship between the volume of the geometry obtained

Upper height of bevel: 6 * 8 / 10 = 4.8cm
Rotate with 6cm side: volume = л * 8 * 8 * 6 / 3 (the radius of the bottom circle is another right angle side 8)
=128л
Rotate with 8cm side: volume = л * 6 * 6 * 8 / 3 (at this time, the radius of the bottom circle is another right angle side 6)
=96л
Rotate with 10cm edge: volume = л * 4.8 * 4.8 * 10 / 3 (at this time, the radius of the bottom circle is 4.8 high above the hypotenuse)
=76.8л