1. Objective: To identify regular polygons. To find area, perimeter and circumference of basic shapes. Perimeter, Circumference, Area Name Class/Period Date

2. Vocabulary A polygon is a closed plane figure formed by three or more segments following these rules: Each segment intersects exactly two other segments at their endpoints. No two segments with a common endpoint are collinear. Each segment is called a side. Each endpoint of a side is a vertex.

3. Vocabulary (continued) Area is the amount of space a 2- dimensional shape takes up. Perimeter is the distance around a 2- dimensional shape. Circumference is the distance around a circle.

4. Concept Summary - Perimeter Square Side length, s P = 4s Triangle Side lengths a, b, and c, Base b, and height h P = a + b + c Rectangle Base b and height h P = 2b + 2h or = 2(b + h) Circle (circumference) Radius r and diameter d C = πd or C = 2πr

5. Concept Summary - Area Square Side length, s A = s 2 Triangle Side lengths a, b, and c, Base b, and height h A = ½bh Rectangle Base b and height h A = bh Circle (circumference) Radius r and diameter d A = πr 2

6. Postulate 1-10: Area Addition Postulate The area of a region is the sum of the areas of its non-overlapping parts.

7. Exit Ticket What would the units be for perimeter (or circumference) and area if the side lengths are measured in feet? Inches? Miles? Centimeters? Kilometers? Homework Use the distance and perimeter formulas to find perimeter for Figures 1-6 and the figures for Problems 3 and 5 on your A Visit to Gridland Packet.