Draw a triangle with CSS and entities to explain the principles

.test{ width:0;height:0;margin:0 auto;border:6px solid transparent;border-top: 6px solid red;}

 

1. The principle of sharing is used

Box is a rectangle or square, from the center of the shape, the four corners vertically and horizontally divided into four parts.

2. implement the code

The first step to ensure that the elements are block-level elements

The second step of the element border

Step frame not to be displayed using transparent color