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Given the cube abcd-a1b1c1d1 with side length a, O is the center of the bottom a1b1c1d1, e is a point on the edge A1B1, and the length of AE + EO is the smallest, then the minimum value is Why do I think it's a got it.. I always calculate a1e + E0 depressed
The original cube is expanded into a plane figure, using the most segment of the line between two points. The figure is too difficult to draw, and the result is that the root sign 10A divides by 2
(see clearly, it's the midpoint of A1B1, not AB)
If we know that the height and volume of a regular pyramid whose vertices are on the same sphere are 3 and 6, then the surface area of the sphere is 0
If the radius of the sphere is 2 and the surface area of the sphere is 16 π, make a regular pyramid figure p-abcd passing through P point, make a vertical line perpendicular to the surface ABCD, and intersect with the surface ABCD at 0 point, then Po is the height of the regular pyramid. According to the volume formula of the pyramid, v = 1 / 3 × bottom area × height, the side length of the bottom surface is: root 6 connecting OB and OC, it is easy to know that △ BOC is an isosceles right triangle
RELATED INFORMATIONS
- 1. What is the surface area of a regular pyramid whose vertices are on the same sphere, whose height is 3 and volume is 6
- 2. 1993 + ABC = 2dde abcd-cdc = ABC what numbers do a, B, C and e represent? ABCD represents a number, but not the same number
- 3. As shown in the figure, in the parallelogram ABCD, the bisector of ∠ ABC intersects CD at point E, and the bisector of ∠ ADC intersects AB at point F. try to judge whether AF and CE are equal, and explain the reason
- 4. In △ ABC, ab = BC, AB is the height of BC side, AE is the bisector of ∠ BAC, ead = 48 ° to find ∠ ACD
- 5. It is known that BD is the middle line of the triangle ABC, and the perimeter of the triangle abd is 2cm longer than that of the triangle BCD. If the perimeter of the triangle ABC is 18cm and AC = 40cm, the lengths of AB and BC are obtained
- 6. In the triangle ABC, D and E are the points of the edges of AC and BC respectively, and EC: EB = 1 / 3. It's troublesome to find the values of BC: be, DC: AC and ad: AC
- 7. In the triangle ABC, ab = AC, angle a = 120 degrees, D is the midpoint of BC, De is perpendicular to AB and E, and the ratio of AE to EB is calculated
- 8. As shown in the figure, be and CF are the heights of △ ABC, M is the midpoint of BC, BC = 10, EF = 5, root 2, and find the area of triangle EFM kuaidiann
- 9. As shown in the figure, at the isosceles right angle △ ABC, ∠ C = 90 °, AC = BC, D is any point on AB, AE ⊥ CD is at e, BF ⊥ CD intersects the extension line of CD at F, CH ⊥ AB is at h, Give AE to g, verify: CE = BF
- 10. As shown in the figure, the elevation angle of C is ∠ CAD = 30 ° from a, the elevation angle of C is ∠ CBD = 45 ° from B, and the angle of view is ∠ ACB when measuring a and B from C=______ Degree
- 11. If you take any point P in the cube abcd-a1b1c1d1 with edge length a, then the probability that the distance between P and point a is not greater than a is: I know everything else, but why is it 1 / 8 of the volume of a sphere centered on a, I think it is 1 / 4!
- 12. In the cube abcd-a1b1c1d1 with edge length a, randomly take the point m in the cube. (1) find the probability that the distance between M and surface ABCD is greater than a / 3 (2) Find the probability that the distance between M and face ABCD and face a1b1c1d1 is greater than a / 3
- 13. In the triangular pyramid p-abc, PA ⊥ plane ABC, ab ⊥ AC, D, e and F are the midpoint of PA, Pb and PC respectively, connecting De, DF and ef (1) To prove the parallel plane ABC of plane def (2) If PA = BC = 2, the cosine value of dihedral angle a-ef-d is obtained when the volume of triangular pyramid p-abc reaches the maximum
- 14. As shown in the figure, in the triangular pyramid p-abc, plane ABC is perpendicular to plane APC, ab = BC = AP = PA = radical 2, angle ABC = angle APC = 90 degrees Q: how to find the area of triangle PBC?
- 15. In the regular tetrahedron ABCD with edge length of 1, e and F are the midpoint of AD and BC, respectively RT
- 16. In tetrahedral a-bcd with equal edge length, e and F are the midpoint of AD and BC respectively. The cosine value of the angle formed by the straight lines AF and Ce on the different planes is obtained
- 17. As shown in the figure, in rectangular ABCD, fold the triangle BCD along BD to the position of triangle BDE, be and ad intersect at o point, and connect AE (1) Proof: the quadrilateral ABDE is isosceles trapezoid; (2) If the angle DBC = 30 ° AB = 2, find the area of quad ABDE
- 18. As shown in the figure, fold a rectangular piece of paper ABCD along AF to make point B fall at B ′. If ∠ ADB = 20 °, then how many degrees should ∠ BAF be to make ab ′‖ BD?
- 19. As shown in the figure, fold a rectangular piece of paper ABCD along AF to make point B fall at B ′. If ∠ ADB = 20 °, then how many degrees should ∠ BAF be to make ab ′‖ BD?
- 20. If the height of the circumscribed cone of a sphere is three times the radius of the sphere, what is the ratio of the side area of the cone to the surface area of the sphere?