1 6 Notes TwoDimensional Figures How can you

1. 6 Notes: Two-Dimensional Figures How can you find the perimeter and area of a polygon in a coordinate plane?

Vocab! Polygon Vertex of the Polygon Examples of Polygons Examples of Non. Polygons A polygon is a closed figure formed by segments such that… • Sides that have a common endpoint are noncollinear • Each Side intersects exactly two other sides, but only at their endpoints A vertex of each angle is a vertex of the polygon named by the letters of its vertices written in consecutive order

Example 1 Determine if the following are polygons. If no, explain why. No, the common endpoint is collinear Yes No, there is a curved side

Vocab! If any of the lines contain any point in the interior of the polygon, it is concave. Concave No lines in the interior of the polygon Convex

Convex vs. Concave State whether the following figures are convex or concave. Concave Convex Concave

Vocab! N-Gon A polygon with n number of sides

Number of Sides 3 4 5 6 7 8 9 10 11 12 N Polygon Triangle Quadrilateral Pentagon Hexagon Heptagon Octagon Nonagon Decagon Hendecagon Dodecagon n-gon

Vocab! Equilateral Polygon A polygon where all sides are congruent Equiangular Polygon A polygon where all angles are congruent Regular Polygons A convex polygon that is both equilateral and equiangular

Example 2 Name the polygon by its number of sides. Then classify it as convex or concave and regular or irregular. Provide a justification in your decision. a) 4 sides = quadrilateral b) 9 sides = nonagon Convex, irregular Concave, irregular

Vocab! Perimeter Circumference Area of Triangle The sum of the lengths of the sides of the polygon Distance around the circle Number of square units needed to cover a surface

Vocab! Area of Square Area of Rectangle Area of Circle

Example 3 Find the area of the figure.

Example 3 cont. b) Find the circumference and area of the figure.