How can a carpenter draw an ellipse according to its size? Charts are the best.

First, find a rope and fix its two ends on two nails. The length of the rope is the length of the ellipse you want to draw. Then draw a crosshair where you want to draw an ellipse, determine the length and height of the ellipse, use it as a fixed point of a high point, and pull half the length of your rope along the crosshair. There are two fixed points at the intersection of the crosshair. Finally, fix the rope at these two points and start painting.

In mathematics, an ellipse is a trajectory in which the sum of the distances between two fixed points on a plane is the same constant.

Woodworking is a craft, a unique technology and a common technology in architecture. It is one of the three traditional industries in China (namely, carpentry, wood industry and carpentry). It is said that when building a house in ancient times, a carpenter must be invited to ward off evil spirits on the day when the house is built and capped! When the evil spirits were suppressed, the carpenter took out his unique tools, stood on the roof and shouted words of good luck to ensure future peace and prosperity! In today's society, "woodworking" has a wide range of professional applications. For example, in the field of housing construction, shipbuilding, landscaping construction, and now the most common decoration field.

In addition to the complete sets of tools commonly used in woodworking, such as axe, bow saw, bow drill, shovel and chisel, spherical drills, claw hammers capable of pulling nails and double saws for logging have also been developed. Long-axis lathes and bicycle beds are also widely used to make furniture and spokes.

Woodworking is a kind of work to complete various wooden projects for the owners in the process of house decoration, and its labor cost accounts for 40-60% of the labor cost of the whole home improvement project. Woodworking concrete construction projects: ceiling project (gypsum ceiling), wood partition project (light steel keel partition), customized furniture project, door cover, window cover project, living room background wall project, porch project. The quality of woodworking technology is directly related to the whole construction effect. However, with the improvement of building materials technology, many woodworking projects have been directly customized by manufacturers, which greatly reduces the decoration cost and greatly improves the quality and sensory effect of customized products.