Compound Area Calculations

6th Grade35 minutes

Learning Objective

I can find the area of compound shapes by breaking them into smaller known figures

Key Concepts

To find the area of an irregular polygon, you must decompose it into different shapes for which you know the area formulas, such as triangles and trapezoids.

The apothem is the distance from the center of a regular polygon to the side at a right angle, and it represents the height of the triangles formed when finding the area.

The area of a regular polygon can be found using the formula: Area = ½ × perimeter × apothem.

Practice Questions

This lesson includes 4 practice questions to reinforce learning.

View questions preview

1. What is the first step in finding the area of a composite figure?

2. A composite figure is made of a rectangle and a square. The rectangle has a length of 8 cm and a width of 5 cm. The triangle has a base of 6 cm and a height of 4 cm. What is the area of the composite figure?

3. Why is it important to carefully choose the correct dimensions when calculating the area of the simpler shapes within a composite figure?

...and 1 more questions

Educational Video

Finding the Area of a Composite Figure | Area of Composite Rectangles

Math with Mr. J

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