How to measure the size of fillet?

This problem can be transformed into the problem of finding the radius of an arc. Take any two points on the arc as tangents, then the tangent point is perpendicular to the tangent, and the two perpendicular lines intersect at one point, which is the center of the circle. Then measure the distance from any point on the arc to the center of the circle, which is the radius of fillet.

Fillet is to replace the original corner with an arc tangent to both sides of the corner, and the size of the fillet is expressed by the radius of the arc. Today, with more and more exquisite web design, the application of rounded corners has become more and more extensive.

JavaScript rounded corners do not need additional HTML tags and pictures, and there are ready-made codes, once and for all. However, in today's virus-ridden world, many users will disable JavaScript. For the website with the highest user experience, if the user turns off JavaScript, all efforts will be in vain.

Fish fillet patent:

Many of Apple's previous patents on iPhone and iPad will more or less contain some practical functions, such as Home button, back contour design or integral glass cover design of front panel.

But the patent obtained this time only describes the appearance design of a device, with rectangular rounded corners. The application scenario of this patent is really too wide. Of course, you can say that the patent figure restricts this patent to devices with a specific aspect ratio, so that other sizes and proportions of flat plates can still not infringe.