These worksheets will introduce your beginning geometry students to the concept of proportions of lengths.

How to Use Proportions to Determine the Length - Ratios and proportions are widely used in math and everyday lives. A ratio is a comparison of two numbers by division. It is the quotient that you get when you divide the first number by the second, non-zero number. Ratios represent proportions, and they are the quotients of numbers divided in a definite order. For this reason, you should be careful to write each ratio in the intended order. For instance, if you want to write the ratio of 2 to 4, you will write it as: 2/4 (as a fraction) or 2:4 (using a colon). To find the ratio of two quantities, such as length, you should express both quantities in the same unit of measure before you determine their quotient. For instance, to compare the value of lengths expressed in meters and centimeters, you should either convert the length in meters to centimeters or the length in centimeters to meters so that you can form a ratio with comparable quantities. If two articles have a similar shape, they are classified as "comparable." When two figures are comparable, the proportions of the lengths of their relating sides are equivalent. If you realize that two articles are comparable, you can utilize extents and cross items to discover the length of an obscure side. The scale factor is utilized to discover relative estimations to make sensible models. Relative methods have a similar proportion. A scale factor is the proportion of the model estimation to the genuine estimation in the easiest structure. In contrast to a scale proportion, the scale factor doesn't think about various units of estimation. A model vehicle with the scale factor of 1:20 implies that the vehicle is multiple times the size of the genuine vehicle. It likewise implies that the vehicle is multiple times the size of the model.

This collection of lessons and worksheets works off of the proportionality of similar figures. You will be given measures of the sides of lengths of a fixed similar polygon and be asked to find the length of corresponding sides. If two figures are similar corresponding sides should have proportional measures of length. This proportion is called the scale factor. You are trying to determine that scale factor. Scale factors are paramount to the process of modeling and taking a design from a screen to a live object. Your beginning geometry students will use these activity sheets to learn how to calculate the length of a given segment by applying the same proportion that is evidenced in other given line pairs.

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Proportions to Determine Length Lesson

This worksheet explains how to use proportions to determine an unknown length. A sample problem is solved, and two practice problems are provided.


Students will use proportions that are presented to find all unknown lengths. Ten problems are provided.

Practice Worksheets

This worksheet explains how to use proportions to determine these measures. A sample problem is solved, and two practice problems are provided.

Review and Practice

Students review how to do use measures that are unknown to find known measures. Six practice problems are provided.

Skill Quiz

Students will demonstrate their proficiency with this skill. Ten problems are provided.

Determine Length Check

You will show this skill in a number of ways. Three problems are provided, and space is included for students to copy the correct answer when given.