Area and Perimeter
Compound Shapes
6.2 and 6.5
Area and Perimeter
of
Compound Shapes
6.2 Perimeter and area of rectangle, triangle, and compound shapes derived from these. Area of trapezoid and parallelogram.
6.5 Areas and volumes of compound shapes. Involving combinations of the shapes in section 6.4
Area and Perimeter
of
Compound Shapes
Context: There are a lot of great mathematical tools that students can develop in this topic. This topic can help make the following concepts and abilities accessible to students:
- Dimension and units, area is a unit-squared, and perimeter is just the unit.
- Unit conversion from distance to area … 1 m2 = 10,000 cm2, even though 100 cm = 1 m
- Deriving formulas
- Writing equations in math
- Problem solving strategies
Big Idea
Students need to understand that area is “space in two dimensions.” For shapes with curves we get to rely on formulas that we do not have to derive or even understand at this level. For polygons, we have some variation and portion of the product of two perpendicular distances.
They also need to understand why the units in area are also squared.
Key Knowledge
Prerequisite knowledge includes basic arithmetic skills and the knowledge of basic two-dimensional geometric shapes.
In this unit students need to come away with the ability to find the area and perimeter of compound shapes by breaking those shapes into smaller pieces.
Pro – Tip
When confused, draw each shape that combines to make the compound shape. Write formulas on each drawing. Then plug in the numbers, then calculate.
Click on the PDF icon to download a Lesson Guide that will pace the PowerPoint. Click on the PowerPoint icon to download the PowerPoint Lesson.
The lessons are intentionally over-built with more material than the time will allow. This way you have more options on how to best serve the needs of your students.
This is a two-day lesson, complete with Lesson Guide which will help you to pace the lesson and understand the objective of each slide in the PowerPoint. There are two homework assignments for the lesson.
Below is a copy of one of the slides from the lesson.
There are two homework assignments for this lesson. The first is pictured below.
To download the first assignment, click here.
To download the second assignment, click here.
