Answer:
It's called proportion.
Explanation:
The equality of ratios are proportional because like for example 2:3 and 4:9 these two ratios are the same. If you break down 4:9 you will get 2:3. So That's how the term proportional is applied. If we apply these ratio on a triangle they would look the same but just one is small and one is large and we can get it bigger by increasing the ratios. But the difference bwtween the ratios would be same so they are all proportional