Lesson Plan

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.

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. -- Standard 6.G.A.1