1, rectangle: the opposite sides are parallel to each other and the adjacent sides are perpendicular to each other. A rectangle consists of vertical lines and parallel lines.
2. Square: First, plan a circle with the garden, and draw the diameter of the circle. The vertical line passing through the center of the circle with the diameter intersects the circle at two points, and two mutually perpendicular diameters are connected with the four points where the circle intersects to form a square. A square is a special parallelogram. That is, a group of parallelograms with equal adjacent sides and a right angle is called a square, also known as a regular quadrilateral. A square has all the characteristics of a rectangle and a diamond.
3. Triangle: divided into equilateral triangle, isosceles triangle and right triangle. If three sides are known, the two endpoints of one side are regarded as two center points, and the other two sides are regarded as two radius circles, and the focal points are connected to form a triangle. If we know an angle twice, we can use compasses in the same way. No matter which angle it is, there will be two ways to draw a triangle, because we don't know whether this angle is the included angle of a known angle. If we know which side of two angles, we can only draw a triangle with compasses.
4. Circle: Draw a circle with your fingers. With the thumb as the center and the distance between the index finger and the thumb as the radius, the figure formed by turning once is a circle. Then circle with rope, thumbtack and strokes. Fix one end of the rope with a thumbtack as the center of the circle, tie the pen to the other end of the rope, straighten the rope with a radius, and the figure formed by the rope rotating around the circle is a circle.
Draw a circle with a compass. Fix one needle of the compass on the book as the center of the circle, take the distance between two needles of the compass as the radius, and the figure formed by one rotation of the compass is a circle. Finally, draw a circle with the circular surface of the object. Hold down the circular surface of the object and draw a circle on the circumference of the circular surface of the object with a pen to form a circle.
5. Trapezoid: divided into isosceles trapezium and right-angled trapezium, and the upper and lower bottom surfaces of the trapezium are parallel. The center line of the trapezoid is parallel to the two bottoms and equal to half of the sum of the upper and lower bottoms. The diagonal lines of the isosceles trapezoid are equal. A set of quadrangles with parallel opposite sides and another set of quadrangles with non-parallel opposite sides are trapezoid. To draw a trapezoid, first determine the length on a piece of paper, and then draw two parallel line segments.
The drawing method of right-angle trapezoid is: first draw a ladder diagram on the plane, and establish a trapezoidal three-dimensional diagram on the body shape. At the upper bottom of the trapezoid, a parallelogram extends. Draw a ladder diagram with the same size on the extended parallelogram, and connect its vertices to complete the trapezoidal three-dimensional diagram.