How do i set up ratios and properties to solve the geometric problems?

 A ratio can be width over length. The width is the shortest side and the length can be known as the longest side. Another way a ratio can be presented is ratio=ratio which is using corresponding parts.Ratios are indicated also by writing the two values with a colon between them. For example 3 to 9 can also be expressed as 3:9. A ratio is also a number relating two numbers or two quantities of the same kind. When one ratio is set equal to another ratio, it is said that they are proportional. You can also try setting up porprotions while using word problems when you might be using two comparisions
Porportions are two ratios that equal eachother. When using or setting up proportions you may have similiar triangles and sometimes one of the parts of the proportion is missing.  Similiar means same shape, but different sizes.