As shown in the figure, the edge length of cube abcd-a1b1c1d1 is 8, m, N, P are the midpoint of A1B1, ad, B & nbsp; B1 respectively. (1) draw the intersection line between the plane passing through point m, N, P and plane ABCD and the intersection line with plane bb1c1c1c; (2) let the plane PMN and edge BC intersect at point Q, and calculate the length of PQ

As shown in the figure, the edge length of cube abcd-a1b1c1d1 is 8, m, N, P are the midpoint of A1B1, ad, B & nbsp; B1 respectively. (1) draw the intersection line between the plane passing through point m, N, P and plane ABCD and the intersection line with plane bb1c1c1c; (2) let the plane PMN and edge BC intersect at point Q, and calculate the length of PQ

(1) As shown in the figure: ∵ MP ⊂ plane abb1, ∵ the intersection point K between MP and bottom ABCD must be on the intersection line AB between side abb1 and bottom ABCD, ∵ the intersection line between the plane passing through points m, N, P and plane ABCD is NK, (k is on the extension line of line AB), and the intersection line between MP and plane bb1c1c1c is PQ (q is on line BC). ∵ BK ∥ A1B

Let m be the midpoint of edge BB 'of cube abcd-a'b'c'd', and try to draw the intersection of plane a'c'm and plane ABCD
I still don't understand. This is the 10th question on page 28 of senior high school mathematics compulsory 2 I hope that some handsome and beautiful women have the right answer.

Connect the midpoint N and point m of a'c ', and extend the extension line of nm and DB to intersect at point O. through point O, make a parallel line of AC, which is the intersection line of plane a'c'm and plane ABCD