Timothy Hamrick
Dr. Ed Dickey
EDSE J660
6 December 2012
Assessment Project – Construction Portfolio
The Lesson
For this project, students will have been given background lesson explaining
geometric constructions and given practice working with the manipulatives of the
straightedge and compass. Students will be introduced to the basic constructions of
finding the midpoint of a given line, creating a perpendicular bisector of a line,
bisecting an angle, constructing a line parallel to a given line, and a line
perpendicular to a given line. These five constructions fulfill the SC Standard G 2.5.
For each construction, students are given step-by-step instructions of how to create
the construction. The importance of clean swoops from the compass and straight
lines drawn from a straightedge are stressed. Students are given an opportunity to
practice the constructions in class and receive feedback on their constructions
either informally or on quizzes. As a result of the lesson, students should be able to:
1) Find the midpoint of a given line segment.
2) Bisect a given angle.
3) Construct a perpendicular bisector of a given line.
4) Construct a line parallel to a given line.
5) Construct a line perpendicular to a given line.
Assessment Strategy
As a cumulative assessment for this lesson, students will be asked to create a
construction portfolio. They will be given five constructions to make and explain
why they work. These constructions will rely on the five basic skills that they were
taught in the lesson as well as some other things mentioned in class (i.e. what a
square or equilateral triangle is).
The manipulatives used here are a straightedge and compass. The students, through
working with these manipulatives will gain a better understanding of many of the
geometric concepts such as perpendicular and parallel.
Construction Project
For this Construction Project, you will be required to use the skills that we have
learned in class as well as think outside of the box. All constructions must be done
with a straightedge and compass. Clean, clear construction markings are required to
receive full credit. Please label all constructions. No free-handing!
There are five constructions to be completed, each worth 10 points. Constructions
will be graded based on completeness, correctness, evidence of construction
markings, and an explanation of why the construction is valid geometrically.
Construction 1: A Square.
A square has four equal sides and four right angles. When constructing your square,
think about how to create perpendiculars and get congruent segments.
Construction 2: An Equilateral Triangle.
An equilateral triangle has three equal sides (and three equal angles). When
constructing your equilateral triangle, consider how to get equal segments.
Construction 3: A Line Perpendicular Through A Point Not On The Line.
Begin by drawing a line. Now place a point somewhere on your paper not on the line
(it will be easier on you if you make the point reasonable close to the line).
Construct a line perpendicular to your first line that passes through the point you
chose.
Construction 4: The Incenter of A Triangle.
The incenter of a triangle is the point that the angle bisectors of the three angles of a
triangle meet. Construct the incenter of a triangle by bisecting the three angles and
determining where they meet.
Construction 5: The Circumcenter of A Triangle.
The circumcenter of a triangle is the point that the perpendicular bisectors of the
three sides of a triangle meet. Construct the circumcenter by constructing the
perpendicular bisectors of each side and finding where they meet.
Each construction will be graded using the following rubric:
Category:
Completeness:
Correctness:
Evidence of
Construction:
0 points
1 point
2 points
3 points
The construction
isn’t completed.
The
construction is
completed.
N/A
N/A
Incorrect
procedures were
used; the student
did not construct
what was
intended.
Incorrect
procedures
were used to
arrive at a
correct
construction.
Correct
procedures
were used but
the end product
is not exactly
what was
intended.
The
construction is
carried out in a
correct way and
does what is
intended.
No construction
markings are
shown; not
obvious that the
construction was
done using a
compass and
straightedge (i.e.
free-handing).
A few
construction
markings that
show a general
following of
correct
procedures; no
markings, but
clearly done
with a compass
and
straightedge.
Some
explanation
given; mostly
incorrect
geometry
concepts
applied; no
geometry
involved in
explanation.
All construction
markings
shown, but
incorrect
construction;
majority of
construction
markings that
show the
correct steps,
but some
missing.
Parts of the
explanation are
missing, but
general idea;
some incorrect
geometry.
All construction
markings are
clearly shown
that led to a
correct
construction.
No explanation is
provided.
Explanation:
A full
explanation is
given using
correct
geometry
concepts.
Total ___________________ / 10