# Ratio of Perimeters and Areas Worksheets

How to Evaluate the Ratio of Perimeter and Area of Similar Rectangles - When you have two rectangles that are similar their corresponding angles are equal, and they are set to the same proportion. We can think of it is a one rectangle is scaled up or down from the other. This would also mean that their perimeter and area also exist between each other in a scale factor as well. We can therefore use similar rectangles to determine all types of unknown measures that exist within them. When you are given that two polygons are similar and you know a good bit about just one of the figures, you have a wealth of information that you can use to find all types of missing measures. You will find this math technique used often in the physical construction of homes and buildings of all types.

• ### Basic Lesson

Guides students solving equations that involve an Permutations & Combinations. Demonstrates answer checking. Two △ are similar. The sides of the first △ are 7, 9, and 11. The smallest side of the second △ is 21. Find the perimeter of the second △. The ratio of the smaller sides of the triangles 7:21 or 1:3 The perimeter of the smaller triangle is 27 Set up a proportion 1:3 = 27:x.

• ### Intermediate Lesson

Demonstrates how to solve more difficult problems. Two polygons are similar. If the ratio of the perimeters is 1:8, find the ratio of the corresponding sides. The ratio of the perimeter is the SAME as the ratio of the corresponding sides.

• ### Independent Practice 1

A really great activity for allowing students to understand the concept of Ratio of Perimeters & Areas. Two triangular roofs are similar. The ratio of the corresponding sides of these roofs is 3:4. If the altitude of the smaller roof is 12 feet, find for larger roof.

• ### Independent Practice 2

Students work on Ratio of Perimeters and Areas in assorted problems. Two polygons are similar. If the ratio of the perimeters is 12:13, find the ratio of the corresponding sides.

• ### Homework Worksheet

Students are provided with problems to achieve the concepts using the ratio between shapes and their perimeters and areas.

• ### Skill Quiz

This tests the students ability to evaluate a variety of Ratio of Perimeters and Areas.