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