#### Math - 2018-19

# 3.12 - Polygons

**The student will **

a)
**define**
polygon;

b)
**identify**
and **name** polygons with 10 or fewer sides; and

c)
**combine**
and **subdivide** polygons with three or four sides and **name** the resulting
polygon(s).

*Adopted: 2016*

### BIG IDEAS

- So that I can solve problems in real-life and in geometry using representations of polygons
- So that I can recognize the shapes that are all around me

### UNDERSTANDING THE STANDARD

- A polygon is a closed plane figure composed of at least three line segments that do not cross.
- Polygons may be described by their attributes (e.g., sides and vertices). Line segments form the sides of a polygon and angles are formed by two line segments coming together at a vertex of a polygon.
- A rectangle, square, trapezoid, parallelogram, and rhombus are all classified as quadrilaterals.

### ESSENTIALS

**The student will use problem solving, mathematical communication,
mathematical reasoning, connections and representation to**

- Define polygon. (a)
- Classify figures as polygons or not polygons. (a)
- Identify and name polygons with 10 or fewer sides in various orientations:
- triangle is a three-sided polygon;
- quadrilateral is a four-sided polygon;
- pentagon is a five-sided polygon;
- hexagon is a six-sided polygon;
- heptagon is a seven-sided polygon;
- octagon is an eight-sided polygon;
- nonagon is a nine-sided polygon; and
- decagon is a ten-sided polygon. (b)

- Combine no more than three polygons, where each has three or four sides, and name the resulting polygon. (c)
- Subdivide a three-sided or four-sided polygon into no more than three parts and name the resulting polygon(s). (c)

### KEY VOCABULARY

*Updated: Aug 22, 2018*