The theory is more general, extending beyond the null circle, and connects naturally to Einstein's special theory of relativity. For instance if one package of cookie mix results in 20 cookies than that would be the same as to say that two packages will result in 40 cookies. In practice, a ratio is most useful when used to set up a proportion â that is, an equation involving two ratios. There are two laws regarding law of proportions . Proportions can be used to calculate metrics such as length, weight, sizes and percentages as well. Law of Definite Proportions Definition . Proportions, on the other hand, can simply be defined when two ratios are equal to each other. A proportion is a name we give to a statement that two ratios are equal. These ratios can be of definable quantities such as shapes and sizes or similar numbers such as fractions. Mathematical beauty is the aesthetic pleasure typically derived from the abstractness, purity, simplicity, depth or orderliness of mathematics. The author in this video explains the concept of fundamental rule of proportions. This math tool allows you solve ratios in any of the following situations: By specifying two numbers (A and B in the first fraction area) from the four numbers of the proportion (decimals are allowed) it will display the complete and true ratio by filling in the right values for the rest of two numbers (C and D); A proportion on the other hand is an equation that says that two ratios are equivalent. Typically, a proportion looks like a word equation, as follows: For example, suppose you know that both you and your friend Andrew brought the same proportion of scarves to caps. Fundamental rule of proportions means cross multiply. It can be written in two ways: two equal fractions, or, using a colon, a:b = c:d; When two ratios are equal, then the cross products of the ratios are equal. That is, for the proportion, a:b = c:d , a x d = b x c He explains that to arrive from an equation which has fractions into the one without equation multiply the top of left side with the bottom of right side and equal it with bottom of left side multiplied with top of the right side. This course is meant for mathematics majors, bright high school students, high school teachers, engineers, scientists, and others with an interest in mathematics â¦ The law of definite proportions states samples of a compound will always contain the same proportion of elements by mass.The mass ratio of elements is fixed no matter where the elements came from, how the compound is prepared, or any other factor. '; Proust worked with 2 samples of same compound Cupric carbonate ( one was it's natural form & the other one was synthetic . $$\frac{20}{1}=\frac{40}{2}$$ A proportion is read as "x is to y as z is to w" How does this proportion calculator work? LAW OF CONSTANT OR DEFINITE PROPORTIONS; By French chemist Joseph Proust ' A chemical compound always contains exactly the same proportion of elements by mass .