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Learning Goal
1 of 4 in this cluster›
Find the area of right triangles, other triangles, special quadrilaterals, and polygons
Start lessonBegins with Area of triangles · Slides
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
- Lesson Plan →Objectives, pacing and practice, built from this lesson's brief.
- Guided Notes →One page your students fill in and keep.
- Exit Ticket →Three items at the end of class. No student accounts.
- Re-teach →After an exit ticket: who missed what, and what to do tomorrow.
- Homework →Assign practice; it grades itself.
6.G.A.1
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.
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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.
What you'll learn
- Find the area of a right triangle by recognizing it as half a rectangle whose sides are the legs.
- Find the area of any triangle by enclosing it in a rectangle and halving, using A = 1/2(base)(height).
- Find the area of a parallelogram by decomposing into a triangle and trapezoid that re-form a rectangle, using A = (base)(height) where height is perpendicular to the base.
- Find the area of a trapezoid by either decomposing into two triangles or composing with a rotated copy into a parallelogram, using A = 1/2(b_1 + b_2)h.
- Find the area of an irregular polygon by decomposing into triangles and rectangles (or by completing a bounding rectangle and subtracting), and compute the total.
- Solve real-world problems that require finding a polygon's area and using that area to answer a question about cost, coverage, or count.
Slides
Step through the lesson, or watch it as a narrated video • 2 slide decks
1
Area of triangles
✓ Start here2
Area of quadrilaterals and polygons
Practice
Try it on your own
Animated Videos
Short animated explanations of the key idea • 5 animated videos
Area of a Triangle: Half the Enclosing Rectangle
Area of a Parallelogram: Rearranging Into a Rectangle
Area of a Trapezoid: Why Both Parallel Sides Count
Area of Irregular Polygons by Decomposition and Completion
Using Area to Answer a Real-World Question
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