When used as recommended, CCA-treated wood is harmless to. people, plants, and animals. Its use provides environmental. benefits as well as decades of service. Specify Wolmanized Â® wood and plywood for applications in which conditions conducive to termites and fungal decay are present.
A quadrilateral is a four-sided polygon with four angles. There are many kinds of quadrilaterals. The five most common types are the parallelogram, the rectangle, the square, the trapezoid, and the rhombus. Move your mouse cursor over the figures at the right to learn more.
Identifying and Classifying Polygons. When people hear the word geometry, they tend to think about shapes. These shapes surround their lives each and every day. Many of these shapes, or polygons, can be described as flat closed figures with 3 or more sides. Polygons are two-dimensional objects, not solids. Polygons are classified and described by the number of sides, the kind of angles, and whether any of the sides are the same length (or congruent). Many polygons have special names. This figure shows the most common polygons. Notice that we identified a 4-sided polygon as a quadrilateral. More commonly, you'd call this shape a rectangle, but a rectangle is only one kind of quadrilateral. A rectangle is a special quadrilateral where opposite sides are congruent -- that is, the same length -- and each angle is a right angle.