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PERIMETER AND AREA OF TRIANGLES AND QUADRILATERALS

Perimeter is the total distance around a closed figure.  We add up the length of all the sides to calculate perimeter.  Some shapes have formulas to simplify the computations.  First we will look at formulas for finding the perimeter of a rectangle.  Then we will expand our understanding of perimeter formulas by finding the perimeter of triangles, parallelograms, and squares. Perimeter is measured in regular units.

Area is the coverage within a closed figure.  We find the number of square units it takes to cover the area of the figure.  Some shapes have formulas to simplify the computations.  We will find the area of rectangles and triangles, and then we will expand our understanding of area by finding the area of squares and parallelograms.  Area is measured in square units.

Perimeter Formulas for a Rectangle

Perimeter Formulas for Triangle, Parallelogram, and Square

Area of a Rectangle and a Triangle

Area of a Square and a Parallelogram

Below are additional educational resources and activities for this unit.

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Unit 21 Area and Perimeter Formulas

Unit 21 Perimeter of Triangles Worksheet

Unit 21 Area of Triangles Worksheet

Unit 21 Area and Perimeter of Quadrilaterals Worksheet