Lesson Plan
Title: Geometry – plane figures
Content Area/s: Math
Grade level: Third
Time Frame: 90 minutes
Date: 4/29/15
SOL: Math 3.14 The student will identify, describe, compare, and contrast characteristics of plane
and solid geometric figures (circle, square, rectangle, triangle, cube, rectangular prism, square
pyramid, sphere, cone, and cylinder) by identifying relevant characteristics, including the number of
angles, vertices, and edges, and the number and shape of faces, using concrete models.
Related SOLs: 3.15, 3.16
Technology SOLs: n/a
Lesson Objectives:
The student will: be able to identify, describe,
compare, and contrast characteristics of plane
geometric figures (circle, square, rectangle,
triangle)
Resources (Text & Technology):
 Plane Geometric Figures Sorting Chart
 Plane Geometric Figures
 Ziploc bags
 Properties of Plane Geometric Figures
worksheet
 Solid geometric wooden figures
 Solid geometric figures sorting chart
 Document camera
 https://jr.brainpop.com/math/geometry/planesh
apes/
Instructional Procedures:
Initial Activity:
Show students the brainpop video on plane figures.
Bring students to the board and display A, E, I, G. Ask students to name what shape each of them
are. Draw the shape on the board bigger, label them with shape names, and then ask the following
questions:
Vertex/Vertices
1. [Circle a point on the rectangle] Does anyone know what this point is called?
2. If they don’t know it is called vertex, spell it on the board for them, say the word, and have
students echo. Then, tell them that when there is more than one, it’s pronounced vertices. The
rectangle has four vertices.
3. Ask students how many vertices there are on a triangle? [3 – circle the vertices for them]
4. How many are on a square? [4]
5. So if a vertex is the point where two line segments come together, does a circle have a vertex?
[No]
Side(s)
1. [Circle a side on the rectangle] Does anyone know what this line between two vertices is
called?
2. If they don’t know it is called a side, spell it on the board for them and say the word. The
rectangle has four sides. Trace the sides for students on the rectangle on the board.
3. Ask students how many sides there are on a triangle? [3 – trace the sides for them]
4. How many are on a square? [4]
5. So if a side is the point between two vertices, does a circle have a side? [No]
Angle
1. [Trace an angle on the rectangle] Does anyone know what this is called when 2 lines
cross/intersect? What do they form?
2. If they don’t know it is called an angle, spell it on the board for them, say the word, and have
students echo. The rectangle has four angles. Trace the angles for students on the rectangle
on the board.
3. Ask students how many angles there are on a triangle? [3 – trace the angles for them]
4. How many are on a square? [4]
5. So if an angle is where 2 lines intersect, does a circle have an angle? [No]
Right angle
1. Tell students that an angle that forms a perfect is a right angle. A book has right angles, paper
has right angles, and a table has right angles.
2. Mention to students that there are three types of angles; a right angle is one of them. There
are angles that are smaller than a right angle and angles that are bigger. But, today we only
want to focus on identify right angles.
3. Ask students which two shapes have right angles. [square and rectangle]
Content:
Distribute copies of the Plane Geometric Figures Sorting Chart. Go over/read through the different
properties at the top. Put students into small groups of three, and give each group a bag containing a
set of plane geometric figures. Have each group complete the sorting chart, using the figures in their
bag. When finished, leave the Sorting Chart on desk.
*Students who finish early may pick up a solid shapes worksheet and complete the chart to the best
of their ability. Turn in to the math box. Once finished with this, they can see the teacher for a
challenge activity.
Use the document camera to check the Plane Geometric Figures Sorting Chart as a class. Ask
questions such as, “What did your group notice about figures H and E?” “What are figures G, C, and
K called?” “Are figures I and D the same shape? [yes] Do they have the same area? [no]” “How are a
square and a rectangle similar? How are they different?”
Closing Activity:
As a class, complete the Properties of Plane Geometric Figures worksheet. Then have students cut
and glue into math journal.
Assessment/s:
 Formative: did students participate in
discussion and classwork throughout the
lesson?
 Formative: Completion and accuracy of the
sort and journal page.
Extension Activities/ Interdisciplinary Links:
 (Supplies: grid paper, pencil, mystery
picture script) Students will take turns
drawing a mystery picture using plane
geometric shapes. Partner #1 will read the
script, slowly step by step, as partner #2
tries to draw the mystery picture. When
finished, students can check the drawing
and its accuracy with the key in the back.
Partners will reverse roles and draw a new
mystery picture.
Differentiation Strategies/Activities:
 Check on student progress during
guided/independent practice/toss and talk
 Once figures are cut out and labeled, have
students trace them on paper. Some students
find that tracing a shape is helpful for
remembering it. Have students label each
traced figure.
 Create poster-size geometric figures, and
display them in the classroom.
Observations/Recommendations for Future Use:
Have students use whiteboards during the initial activity to answer questions about # of sides,
vertices, and angles.
Have students do a walking field trip and identify plane figures throughout the classroom or school as
an initial activity to introduce the unit.