The problem of the vertical relation of the solid geometry in the second grade of senior one What is the vertical line of a plane, what is the vertical plane of a straight line, what is the vertical foot, what is the vertical line segment, and what is the distance from this point to the plane?

The problem of the vertical relation of the solid geometry in the second grade of senior one What is the vertical line of a plane, what is the vertical plane of a straight line, what is the vertical foot, what is the vertical line segment, and what is the distance from this point to the plane?

If a line is perpendicular to a plane, it is the vertical line of the plane. This plane is called the vertical plane of the line. The intersection of the vertical line and the plane is called the perpendicular foot
A line segment from a point to a perpendicular foot is called a perpendicular segment. The length of the perpendicular segment is called the distance from the point to the plane

It is known that in the polyhedral abcdfe, the quadrilateral ABCD is a rectangle, ab ⊥ EF, AF ⊥ BF, plane abef ⊥ plane ABCD, O and m are the midpoint of AB and FC respectively, and ab = 2, ad = EF = 1. (I) prove: AF ⊥ plane FBC; (II) prove: om ⊥ plane DAF

(I) plane abef ⊥ plane ABCD, plane abef ∩ plane ABCD = abbc ⊂ plane ABCD, and quadrilateral ABCD is rectangular ⊥ BC ⊥ AB, ∩ plane abef ⊂ plane abef ⊂ BC ⊥ AF ⊥ BF ⊥ AF, BC ∩ BF = B ∩ AF ⊥ plane FBC; (II) take the midpoint n of FD to connect Mn and an, then Mn ⊥ CD, and Mn = 12CD, and quadrilateral ABCD is rectangular, ∩ Mn ⊥ OA, and Mn = OA ⊥ quadrilateral aomn is flat Row quadrilateral, ∥ om ⊄ an ⊄ planar DAF, an ⊂ planar DAF ⊂ om ⊉ planar DAF

Summary of the second knowledge points of mathematics required in senior one

The definition of the inclination angle of a straight line: the angle between the positive direction of the X axis and the upward direction of the straight line is called the inclination angle of a straight line. In particular, when a straight line is parallel to or coincident with the X axis, we stipulate that its inclination angle is 0 degree