MindMap Gallery Preliminary geometry
This preliminary mind map of geometric figures summarizes the knowledge of points, lines, surfaces, bodies, straight lines, rays, line segments, angles, geometric figures, etc. Everyone is welcome to learn.
Edited at 2023-07-16 10:09:50This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
Preliminary geometry
Point, line, surface, body
The intersection of lines is a point, which is the most basic form of geometry.
Lines are divided into straight lines and curves, and are the parts where surfaces intersect.
The body is surrounded by planes and curved surfaces.
Geometry is also called a body.
A point moves to form a line, a line moves to form a surface, and a surface moves to form a body.
Line, ray, line segment
straight line
There are no endpoints, and the straight line represents a straight line AB, which cannot be extended.
Rays
An endpoint, representing ray AB, can be extended in the opposite direction
line segment
Two endpoints, representing line segment a or AB, can be extended or reversely extended.
Two points determine a straight line
Draw a line segment equal to a known line segment
Metrics
Drawing with ruler and compass
How to compare the size of line segments
Metrics
Overlay method
midpoint of line segment
The point that divides a line segment into two equal segments is called the midpoint of the line segment.
If point m is the midpoint of line segment ab, then AM=BM=1/2AB, AB=2AM=2BM
horn
horn
This kind of geometric figure can vividly represent angles. The intersection of the hour hand and the minute hand and the sides of the triangle ruler are all images of angles.
A figure composed of two rays with common endpoints is called an angle
Degrees, minutes and seconds are commonly used units of measurement
Degree: A circumferential angle is divided into 360 equal parts, each part is 1 degree of angle, recorded as 1°
Cent: Divide an angle of 1 degree into 60 equal parts. Each part is called an angle of 1 minute and is recorded as 1'
Second: Divide the angle of 1 minute into 60 equal parts. Each portion is called the angle of 1 second and is recorded as 1''
Angular Comparisons and Operations
Generally starting from the vertex of an angle and dividing it into two equal angles, the ray is called the bisector of the angle.
Supplementary angles and supplementary angles
remaining angle
Two angles whose sum is 90° are supplementary angles, and they are supplementary angles to each other.
Complementary angles of same angles (congruent angles) are equal
supplementary angle
If the sum of two angles is 180°, they are complementary angles.
Supplementary angles of same angles (congruent angles) are equal
Project learning Design and make rectangular-shaped packaging cartons
observe, discuss
design production
communicate, compare
evaluation, summary
consolidate, improve
Geometry
Cuboids, cylinders, spheres, rectangular (square) squares, circles, line segments, points, etc. are all geometric figures. Triangles, quadrilaterals, etc. learned in primary school are also geometric figures. They are all derived from the shapes of various objects.
Some figures are not in the same plane, such as cuboids, cubes, cylinders, cones and spheres, etc. They are called three-dimensional figures.
cylinder
A cylinder is a polyhedron with two parallel and congruent faces, and the intersection lines of the other adjacent faces are parallel. Cylinder and prism are two forms of cylinder.
cone
A cone is a spatial shape defined by a closed plane base and a line segment connecting a point on the base boundary, including cones and pyramids.
Line segments, angles, triangles, rectangles, circles, etc. are all in the same plane, and they are plane figures.
Three-dimensional figures and planar figures are different geometric figures, but they are related. For example, the sides of a cuboid are rectangular.
A three-dimensional figure is surrounded by a planar figure, which can be cut and unfolded into a planar expansion.
Draw n rays arbitrarily inside the angle Then there are (n 1)(n 2)/2 in the graph