Math Example--Area and Perimeter--Quadrilaterals: Example 15

Topic

Geometry

Description

This example demonstrates how to calculate the perimeter of a rectangle. The rectangle ABCD has a length of 18 units and a width of 12 units. To find the perimeter, we use the formula P = 2(l + w), where l is the length and w is the width. In this case, P = 2(18 + 12) = 2(30) = 60 units.

Understanding the perimeter of rectangles is a fundamental skill in geometry that has numerous real-world applications. This collection of examples helps students visualize and compute perimeters of various quadrilaterals, starting with simple shapes like rectangles and progressing to more complex ones. By exploring different dimensions and shapes, students develop a robust understanding of how perimeter relates to the dimensions of a shape.

Exposure to multiple worked-out examples is crucial for students to fully grasp the concept of perimeter. Each example reinforces the basic principle while introducing slight variations, allowing students to recognize patterns and develop problem-solving strategies. This approach helps build confidence and proficiency in applying formulas and reasoning through geometric problems.

Teacher Script: "Let's examine this rectangle. Notice how it has two different side lengths - we call the longer side the length and the shorter side the width. To find the perimeter, we need to add up all four sides. We could do this by adding 18 + 12 + 18 + 12, but there's a shortcut! We can add the length and width once (18 + 12 = 30) and then multiply by 2 because this sum appears twice in our rectangle. So, 2 × 30 gives us 60 units. Always remember to include the units in your answer! Can you think of any real-life objects that might have these dimensions?"

For a complete collection of math examples related to Area and Perimeter click on this link: Math Examples: Quadrilateral Area and Perimeter Collection.