Final answer:
To find the length of the field, we can set up a proportion using the given ratio of the length and width. The length is found to be 70m.
Step-by-step explanation:
To solve this problem, we can set up a proportion using the given ratio of the length and width. The ratio is 5:3, which means that for every 5 units of length, there are 3 units of width. We are given that the width of the field is 42m, so we can set up the proportion as follows:
(Length)/(Width) = (5)/(3)
Substituting the values, we have:
(Length)/(42) = (5)/(3)
To find the length, we can cross-multiply and solve the equation:
Length = (5 * 42) / 3
Length = 70m