P is the point out of the plane of the parallelogram ABCD, and Q is the midpoint of PA
If AC and BD intersect at O, then OA = OC and ob = OD
In △ PAC, OQ is the median line
∴OQ∥PC
∵ OQ in plane BQD
‖ PC ‖ planar BQD
RELATED INFORMATIONS
- 1. P is a point out of the plane of the parallelogram ABCD. Find a point E on PC to make the PA ‖ face be, and give the proof
- 2. P is a point outside the parallelogram ABCD, and Q is the midpoint of PA
- 3. The bottom surface of the pyramid p-abcd is a square with side length 1, and the side edge PA is perpendicular to the bottom surface ABCD. Moreover, PA = 2. If e is the midpoint of PA, we prove the plane BDE
- 4. The bottom of p-abcd is a parallelogram, the bottom of PA ⊥ is ABCD, e is a point on PA, and the section of PC ∥ is BDE Find the volume ratio of the two parts of the pyramid p-abcd divided by the section BDE
- 5. If the bottom of p-abcd is a parallelogram, the bottom of PA ⊥ is ABCD, the point E is on the side edge PC, and PE = 13pc, then VP − bdevp − ABCD=______ .
- 6. PA is perpendicular to the plane of the square ABCD with side length a, PA = a, then the size of the dihedral angle b-pc-d is It needs a rough process
- 7. Through the vertex a of the square ABCD, make the line PA ⊥ plane ABC, and PA = Pb, then the degree of the sharp dihedral angle formed by plane ABC and plane PCD is? Sorry, wrong number. It's not pa = Pb, it's PA = ab
- 8. Given that PA ⊥ square ABCD, if AB = PA, then the dihedral angle of plane PAB and plane PCD is
- 9. If the line AP is perpendicular to the plane ABCD through the vertex a of the square ABCD, and AP = AB, then what is the dihedral angle between the plane ABP and the plane CDP? (Figure)
- 10. If the vertex a of the square ABCD passes through the AP vertical plane ABCD and AP = AB, then the degree of the dihedral angle between the plane ABP and the plane DCP is Draw a picture
- 11. P is a point outside the parallelogram ABCD, and Q is the midpoint of PA
- 12. Let p be a point in the square ABCD, and the distances from point P to vertex ABC are 1, 2 and 3 respectively
- 13. P is a point inside the square ABCD. The distances from point P to vertex a, B and C are 1, 2 and 3 respectively. Find the side length of the square Using trigonometric function solution, there are two results under the solution. Why should 5-2 √ 2 be omitted?
- 14. A mathematical problem: let p be a point inside the square ABCD, and the distances from P to vertex a, B and C are 1, 2 and 3, respectively
- 15. In the cube abcd-a1b1c1d1, M is the midpoint of CC1. If point P is on the plane of abb1a1 and satisfies ∠ pdb1 = ∠ mdb1, then the trajectory of point P is () A. Circle B. ellipse C. hyperbola D. parabola
- 16. In the cube abcd-a1b1c1d1, M is the midpoint of CC1. If P is on the plane of abb1a1 and satisfies ∠ pdb1 = ∠ mdb1, what is the trajectory of point P? The answer is hyperbola But I think the picture I draw also looks like a parabola Is there a curve? How can I draw only one
- 17. In the square abcd-a1b1c1d1, P is a moving point in the side b1b1cc. If the distance from P to the straight line BC and c1d1 is equal, then the trajectory of the moving point P is? Why a parabola?
- 18. As shown in the figure, in the cube abcd-a1b1c1d1, P is a moving point in the side bb1c1c. If the distance from P to the straight line BC and the straight line c1d1 is equal, the curve of the trajectory of the moving point P is () A. Straight line B. circle C. hyperbola D. parabola
- 19. The perimeter of parallelogram ABCD is 70, the distances AE and AF from vertex a to BC and CD are 10 and 15, respectively
- 20. As shown in the figure, in the pyramid p-abcd, the quadrilateral ABCD is a rectangle, the plane PCD ⊥ the plane ABCD, and M is the midpoint of PC