Download 4.G.2 Properties of quadrilaterals 5-22-12

4th Grade
Properties of Quadrilaterals
Unit 4
Standards addressed by this lesson experience:
o 4.G.2. Classify two-dimensional figures based on the presence or absence of parallel or perpendicular
lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category,
and identify right triangles.
Goal: Students will classify quadrilaterals based on their properties.
Materials Needed:
A set of quadrilateral pieces for the teacher, and sets for each group of groups (see blackline masters:
Parallelogram, Rectangles, Squares, and Rhombuses, you could also make one for trapezoids)
Index cards to check the angles (or a protractor if you have done measuring angles), compare side lengths, and
draw straight lines
Mirrors to check symmetry
Post-it notes
Math Notebooks
Vocabulary:
Polygon- a closed plane figure formed by three or more line segments called sides. Each side intersects exactly
two other sides, but only at their end points. Sides that have common end points are part of the same line.
Parallel lines- Two lines in a plane that do not intersect or touch at any point
Quadrilateral- a quadrilateral is a polygon with four sides (or edges) and four vertices or corners.
Parallelogram- a parallelogram is a convex quadrilateral with two pairs of parallel sides. The opposite or facing
sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of
equal measure
Rectangle- a rectangle is any quadrilateral with four right angles.
Rhombus- a parallelogram in which all sides have equal length
Square- a rectangle with four equal sides and four right angles, also a rhombus with four right angles
Right angle- angle measuring exactly 90 degrees
Acute angle- angle measuring more than 0, but less than 90 degrees
Obtuse angle- angle measuring more than 90 degrees
Last revised 5-4-12
1
Rogers Public Schools
Adapted from Elementary and Middle School Mathematics: Teaching Developmentally, J. A Van de Walle, 2007
4th Grade
Properties of Quadrilaterals
Unit 4
Lesson:
Put students in groups and give each group one type of quadrilateral (either square, rectangle, rhombus, or
parallelogram handout, you could add trapezoid as well) to discuss in the group.
 Ask students to list as many properties of the quadrilaterals they can with attention the sides and
angles. (Students don’t necessarily have to discuss the diagonals or the point symmetry of the figures to
meet the standards, but it would be a good extension for differentiation). Each property listed has to
apply to all the shapes in the group.
 They can use the index cards and the mirrors to check the shapes for size of angles, lengths of sides, and
symmetry.
 Encourage students to use words “at least” when describing how many of something: for example,
“rectangles have at least two lines of symmetry,” since squares- included in the rectangles- have four.
 Have students prepare their property lists under the headings on the sheet.
 Let students do a gallery walk and look at each other’s property lists. Give each student 3 post-it notes
to use as they look at each property lists. Tell them they can add ideas to the property lists as they walk
around.
 Once all students have finished the gallery walk, bring students together for group discussion. Create an
anchor chart for each quadrilateral based on the ideas they students generated during their group work
and the gallery walk.
 Once property lists for the parallelogram, rhombus, rectangle, and square, have been agreed upon, post
them in the class for all to see and have students record them in their Math Notebooks.
Last revised 5-4-12
2
Rogers Public Schools
Adapted from Elementary and Middle School Mathematics: Teaching Developmentally, J. A Van de Walle, 2007