Two triangles are similar and have sides of 8, 12, 28 and 6, 9, 21. what is the ratio of similarity between the two triangles?

To get the ratio, we must pair up one side of a triangle to another side accordingly. In here, we can write the ratio of first side as 8:6. 8:6 can also be written as 8/6. we can simplify it as the common factor is 2, we will then have 4/3. The ratio of similarity is 4:3. 

We can prove if its true by testing the other two sides as well. We will have 12/9 which has a common factor of 3 and 28/21 with a common factor of 7. if simplified, all sides has a ratio of 4:3