Ratio: generally refers to the value obtained by comparing the lengths of two line segments. It is often necessary to reduce points and simplify. People often regard it as the ratio of two numbers in application, so there is a negative ratio.

The ratio can be useful. 1) You can compare the size of two numbers or the length of two line segments. 2) The length of the unknown line segment, the perimeter and area of the figure can be calculated by the ratio; 3) The ratio of two sides of a triangle is equal, the corresponding sides are proportional, and a pair of included angles are equal, so that two triangles are similar.

The calculation of ratio is equivalent to the calculation of fraction. However, the meaning of ratio is usually different from that of division. The former generally refers to the comparison of two numbers, while the latter means more than just the ratio.

I wonder if you are satisfied with this answer?