Learning Resources LRM320B-GUD Introduction, Getting Started with Transparent Geometric Shapes

Introduction
The transparent Giant GeoSoli ds® set includes 10 plastic, three-dimensional
shapes that allow for hands-on study of volume. These shapes can expand
daily m ath lessons while introducing, t eaching, and reviewing geometric
concepts effectively. They all ow students to make concrete connections between
geometric shapes and their associated formulas for volume, as
well as compare the volumetric relationship between each shape.			both of
Most shapes in this set are variations of a prism or a pyramid,
which are pol yhedrons. Polyhedrons are solid figures with flat			sides, or
faces.	Faces may meet at a poi nt, called a vertex,	or at a line, called an
edge.	A prism has two congruent bases; the remaining faces are rectangles. A
pyrami d has one base and the remaining faces are triangles.
Three shapes in this set have curved faces rather than flat ones: the cyl inder,
cone ,	and sphere. Technically, they are not polyhedrons. Even so, a cyl in-

der can be thought of as a circular prism: a figure w ith congruent circular bases and a singl e, rectangular face. A cone can be thought of as a pyramid with a circular base and a face that is a wedge. A sphere is a unique shape with no parallel to prisms or pyramids.

At the outset, learning formulas for the volume of more than a dozen geometric shapes may seem daunting to your students. However, formulas become much easier to remember when students recognize that only the method for calculating the area of a base changes from formula to formula; the other variables of a polyhedronare calculated the same way, regardless ofshape.

Getting Started with Transparent Geometric Shapes

Allow students to become familiar with the manipulatives before beginning directed activities. You may want to explore prisms and pyramids on se parate days. Encourage students to handle, observe, and discuss the shapes. Ask them to write down their observations as t hey make the following comparisons: How are the shapes sim ilar? (With the exception of the sphere, all shape s have the same height. T hey are all three-dimensional. They all have empty spac es inside them.) How are they different? (Some have flat sides, some have c urved sides. Some are box-shaped, some are round, and some are triangle-shaped.) Where have students seen these shapes in the w orld around them? (Great Pyramids

of Egypt, tr affic pylons, fil m canisters, soccer balls, pieces of chalk, b oxes, lipstick tubes, and so on.)

Introduce and identify the following terms: face , edge, verte x or corner, and base . M ention to students that the base of each shape can be identified by its color.

Ask students how they might organize the shapes into categories based on their 3