Let’s Make Some
Skew
Stew!
A chef wanted people to
understand some solid geometry.
To do this, he created a new dish
which only contained food shapes
with edges which were skew to
other edges of the shape. He calls his creation
Skew Stew.
For instance, the rectangular prism above right would go into the Skew Stew since edges
k and m are skewed edges. Edges k and m are skew because they do not intersect and are
not coplanar. You can use two stir sticks to help you figure out whether any edges are „skew‟
or „not skew‟ by fitting them to the edges of each solid.
Take turns sharing the 8 solids. Fill out the table below to determine which of them would go
into the Skew Stew. Then make out your shopping list for Skew Stew in the space
below.
Names within the Groups: _______________________________________________________
______________________________________________________________________________
Name the Solid
Number
of Edges
Any Skewed Edges?
YES
In the Pot
1
Rectangular Prism
2
Triangular Prism
3
Hexagonal Prism
4
Cube
5
Cylinder
6
Triangular Pyramid
7
Square Pyramid
8
Cone
Shopping List for
Skew Stew:
____ ?

NO
Leave Out
Skew Stew Directions
Materials


Folding Geometric Shapes set
long stir sticks or straws. [Your neighborhood QT is a good source.]
Procedures
Number them off into 8 groups.
Spread the 8 solids around the room and have each group gather around a specific shape like
rectangular solid, cone, etc.
Give them 1-1½ minutes to count up the edges and determine if it there are skew edges or not.
Each person in the group must handle the solid and use the stir sticks to show off skew lines.
All figures with polygon bases have multiple sets of skew edges. It‟s the two solids with circular
bases which should create the most discussion.
Evaluation
As you walk around the room you are looking for students to touch, discuss, record, analyze,
and evaluate solids, edges and skews. I expect to make this a daily in-class grade.
Extension
For the cone and the cylinder, you may want to develop the concept of skew with tangents.
This could lead to the discovery of an infinite number of skews and an infinite number of
intersecting lines by starting with tangents, heights and slant heights plus chords and
diameters. We don‟t have to develop the vocabulary at this point just get them observe and
discuss what they see.
So depending on how deep you want to go and the point of view you want to take, students
might say that all of the solids have skewed edges or can create skewed lines. Each „chef‟ then
gets to make the determination whether the cone and/or the cylinder gets to go into the
Skew Stew.
This gives us an opportunity to introduce student to edges before we have to know and use
them, and then return to the idea the next time we use the figures. It gets them to stretch their
imagination to think about abstract concepts like infinity, without have to make it an „official‟
part of the lesson.
If this works out we might have our own little version of Gordon Ramsay‟s “Hell‟s Kitchen” with
people talking about and debating Geometry – something that‟s not easily done.