Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.

Find the area of a parallelogram by decomposing

In this lesson you will learn how to find the area of a parallelogram by decomposing into a rectangle.

Find the area of a right triangle

In this lesson you will learn how to find the area of a right triangle by composing a rectangle.

Find the area of a trapezoid by composing a parallelogram

In this lesson you will learn how to find the area of a trapezoid by composing a parallelogram.

Find the area of polygons by decomposing into triangles, rectangles, …

In this lesson you will learn how to find the area of other polygons by decomposing into triangles, rectangles, parallelograms, and trapezoids.

#### Isolation Drills:

Area of quadrilaterals and polygons

Area of trapezoids, rhombi, and kites

Finding area by composing and decomposing shapes

#### Interactive Practice:

- Angle Classification: Acute, Right, Obtuse – Explanation and questions to answer
- Angle Game – Shoot alien spaceship that matches the angle stated.
- Angles – Students practice their knowledge of acute, obtuse and alternate angles.
- Angles – A twenty slide PowerPoint show with a quiz to be used as a whole class activity
- Area of a Rectangle: Intermediate Level – Worksheet, answers on page 2
- Area of a Right Triangle – Worksheet, answers on page 2
- Area of a Triangle – Three page lesson, practice questions are found on page 3
- Area of a Triangle – Drag the orange dots on each vertex to reshape the triangle. The formula shown will recalculate the area using this method. Several ways to calculate triangle area are listed.
- Area of a Triangle – Several ways to compute the area of a triangle
- Area of a Triangle – Interactive lesson plan from Illuminations
- Area of a Triangle – Explanation, examples and practice exercises to check student understanding
- Area of an Irregular Rectangle – Calculate the area of each figure given
- Area of Complex Figures – Self check, multiple-choice quiz
- Area of Parallelograms – Self check, multiple-choice quiz
- Area of Parallelograms and Trapezoids – Multiple-choice quiz from IXL math
- Area of Parallelograms, Triangles, and Trapezoids – Self check, multiple-choice quiz
- Area of Parallelograms, Triangles, and Trapezoids – Chapter test, multiple-choice quiz
- Area of Plane Shapes – Several plane shapes are listed with the formula for calculating their area, at the end of the page you will find links to ten questions to check student understanding
- Area of Rectangles and Triangles – Worksheet, answers on page 2
- Area of Rectangles and Triangles: Advanced – Worksheet, answers on page 2
- Area of Squares and Rectangles – Multiple-choice quiz from IXL math
- Area of Triangles – Multiple-choice quiz from IXL math
- Area of Triangles – How to find areas of triangles
- Area of Triangles – Self check, multiple-choice quiz
- Area of Triangles and Trapezoids – Self check, multiple-choice quiz
- Areas and Squares – Five multiple-choice questions
- Baseball Geometry – Area of a triangle game from Knowledge Box, you get baseballs to swing at for getting a correct answer
- Basic Geometric Figures – A TAKS worksheet to print and use in class [from the Wayback Machine Internet Archive.]
- Calculating the Area of a Triangle – Explanation, examples, practice exercises, and a quiz designed as a game
- Classifying Angles – Multiple-choice quiz [5 questions]
- Construction of Bicentric Quadrilateral – A mathematical droodle
- Equilateral, Isosceles, and Scalene Triangles – Choose the most restrictive term
- Geometric Shape Flashcards – Quiz, select the correct answer from a pull down menu
- Geometry Building Blocks: Classifying Angles – Explanation and drawings
- Geometry Building Blocks: Classifying Angles – Examples
- Geometry Building Blocks: Classifying Angles – Quiz
- How Do We Measure Angles? – Six page worksheet with explanations and exercises to print and use in class
- How Do You Find the Area of a Triangle – Math video answering the question
- Interactive Quadrilateral – Become familiar with all angles of quadrilaterals in this interactive game.
- Interactive Triangle – Click on the red points in the Java Window to manipulate the triangle. Use the buttons to show the calculated area in each of the three calculations
- Making Triangles – Virtual GeoBoard; interactive site; IWB friendly.Investigating the Concept of Triangle and the Properties of Polygons (from NCTM)
- Measuring Angles – Use a virtual protractor
- Measuring Angles – Practice lining up and reading a protractor while you measure a set of angles in a fun learning activity
- Measuring Angles with a Virtual Protractor – Ten online activities investigating angles. Use this virtual protractor to measure angles you create yourself.
- Measuring Area and Volume – Chapter test, multiple-choice quiz
- Names of Angles – Definition and drawings of each type
- Polygons – Introductory lesson from Math is Fun
- Practice With Quadrilaterals – A twelve question quiz with drawings
- Quad Squad – A quick lesson on classifying and describing quadrilaterals
- Quadrilateral Family – From regents prep
- Quadrilateral Matching – Concentration style quiz
- Quadrilateral Quest – Interactive lesson, drag and drop activity
- Quadrilateral Sorter – Click on a shape to find out about it
- Quadrilaterals – A sixteen slide PowerPoint show
- Quadrilaterals – A wikipedia entry with a large number of drawings
- Quadrilaterals – Explanation, examples and questions to answer
- Quadrilaterals Explained – Lesson on quadrilaterals and activity dragging the dots to form quadrilaterals.
- Quadrilaterals II – A twenty-eight slide PowerPoint show
- Quadrilaterals Quiz – Six multiple choice questions
- Right, Acute, and Obtuse Angles – Figures are shown, decide which is the proper angle
- Right, Acute, and Obtuse Angles – Sort angles into appropriate containers
- Shapes: Quadrilaterals – Explanation and questions to show understanding
- Squaring the Triangle – Learn about how the Pythagorean Theorem works, through investigating the standard geometric proof. Parameters: Sizes of the legs of the triangle.
- Triangle Calculator – Enter values three of the six sides and angles of the triangle and the other three values will be computed. The number of significant values entered will determine the number of significant figures in the results.
- Triangle Explorer – An applet which allows students to study the nature of triangles and their area
- Triangle Explorer – Students learn about areas of triangles and about the Cartesian coordinate system through experimenting with triangles drawn on a grid.
- Triangle Identification – Type of triangle, given its angles – instruction and review, practice, and a quiz
- Triangle Identification – Identify the triangle given its number of sides – instruction and review, practice, and a quiz
- Triangles Side-By-Side – Use geometric vocabulary to describe properties of triangles
- Types of Angles – Definitions, and drawings of each type
- What’s My Quadrilateral – Three different teaching ideas
- Working with Angles – Spy Guys Interactive Lesson 16- Online lesson along with activities and practice for this topic.