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Grade 8:  The Learning Equation Math

32.05 Composite Areas

 3D Objects & 2D Shapes Refresher pp 62-63
Learning Outcomes:

The student will:

Composite areas require knowledge of the area formulae.

## Perimeter and Area

Multiplication Tables: the product of two numbers can be represented by the area of a rectangle where the factors are represented as the dimensions of the rectangle. Notice each square in the area grid is a unit square.

Area of a rectangle is represented by a grid of unit squares. Perimeter is the distance around the outside rectangle.

Area of a square is represented by a grid of unit squares. Perimeter is the distance around the outside square.

Area of a parallelogram is represented by a grid of unit squares. Perimeter is the distance around outside of the parallelogram.

Area of a rhombus is represented by a grid of unit squares. Perimeter is the distance around outside of the rhombus.

Area of a triangle is represented by a grid of unit squares. Perimeter is the distance around outside of the triangle.

Area of a trapezoid is represented by a grid of unit squares. Perimeter is the distance around outside of the trapezoid.

Shape Explorer - perimeter and area on a grid

 Polygon/Circle P = Perimeter C = Circumference distance around the polygon/circle A = Area triangle P = b + c + d or P = s1 + s2 + s3 A = 1/2ab Note: The area of the triangle is half the area of the corresponding parallelogram/rectangle. quadrilateral P = b + c + d + e or P = s1 + s2 + s3 + s4 don't need to memorize the formula in junior high enrichment trapezoid P = b1 + b2 + c + d or P = s1 + s2 + s3 + s4 A = 1/2ab1 + 1/2ab2) simplifies to A = 1/2a(b1 + b2) parallelogram P = 2b + 2c A = bh rhombus P = 4s A = as rectangle P = 2l + 2w A = lw square P = 4s A = s2 chevron don't need to memorize the perimeter/area formulae in junior high kite don't need to memorize the perimeter/area formulae in junior high enrichment regular polygon a = apothem length s = side length n = #sides   pentagon = "five sides" hexatagon = "six sides" heptaagon = "seven sides" octaagon = "eight sides" nonagon = "nine sides" decagon = "ten sides" P = ns A = 0.5ans = 0.5aP circle Circumference is the distance around the circle. C = Circumference C = pd A = Area A =p r2 Polygon/Circle Perimeter/Circumference

Key Terms:

area, composite, 2D figure, congruent, parallel, parallelogram, trapezoid

Prerequisite Skills:

Order of Operations:   Grade 7 Lesson 12.03

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