ACTIVITY 12 PERIMETER AREA OF POLYGONS Formulas Perimeter of a polygon is the sum of the lengths of the sides of the polygon Area is the amount of surface bounded in a closed in a closed region a Triangle a b h c Perimeter P a b c Area ch 2 b Square Perimeter P 4s Area s 2 s s c Rectangle Perimeter P 2 w l Area l w w l d Parallelogram Perimeter P 2 a b Area b h a h b e Regular n gon If the length of each side is s then the perimeter P ns A regular n gon can be divided into n congruent triangles Assume that the area of each triangle is A units square Then the area of the n gon n A Example The perimeter of regular hexagon each side of which is 4cm is 6 4 24 cm EXERCISES 1 Answer True or False If False give a counterexample a b c d Two regions that have the same area are congruent The converse of statement a is true Regions that have the same perimeter are congruent Rectangles that have the same area have the same perimeter 2 Find the area of the shaded region in the square below The length of each side of the square is 4 inches 2 2 2 2 3 A rectangle has a length of 6 inches and a perimeter of 28 inches Find the width 4 A square has side length s inches If the length is tripled and the width is halved find the area of the new figure 5 Find the area of the parallelogram shown 10 cm 16 cm 6 A rectangular garden is to be fenced with 30 ft of fencing What are the dimensions of the gardens largest area 7 The formula for the area of a trapezoid with parallel sides a and b and height h is h A a b Describe a cut and paste process to verify this formula 2 8 9 a b Find the area of regular hexagon each side of which is 4cm Write a lesson plan that describes how you will introduce the topic of Perimeter Area to a first grade class Include the following in the lesson plan Materials Vocabulary Objectives Motivation Real world connection closure assessment