Unit 8 -  Properties of Polygons

During this unit, students investigate the classification of polygons by attributes such as length of sides and size of angles. They solve problems about perimeter, a linear measure, and area, a two-dimensional measure.

Playing “I Spy” Polygons and Angles To help your child continue to investigate the properties of polygons (especially triangles and quadrilaterals) and patterns involving their sides and angles, find figures around the house that fit a rule and play a guessing game. For example, you might describe a mirror by saying, “I’m thinking of something in this room that has two equal sides, at least two equal angles, and at least two parallel sides. What could it be?” Then have your child identify objects that fit that rule, while trying to guess which specific object you were describing. 

Practicing Perimeter Estimating or calculating the perimeter of objects around the house is a good way to help your child use this concept in a variety of situations. There are many examples: the perimeter of a rectangular table, the perimeter of a room or rug, the perimeter of the refrigerator door or sink. You can measure perimeter in standard units of measure (such as inches or centimeters) or in nonstandard units (such as hand widths). 

• Work with your child on estimating perimeters by measuring the perimeter of one object (for example, the sink), and then using this information to estimate the perimeter of a nearby object (for example, the refrigerator door). 

• Look for objects to measure that are other shapes besides rectangles. Can your child begin to estimate the perimeter of circular objects, such as a round table? Find the perimeter of a round table by walking or measuring around the outside of the table. Compare this perimeter with those of rectangular objects such as tables and rugs.