Mosaic Angles
SUBJECT:
Measure, addition/subtraction of angles
TEACHERS:
Jenene Woodruff
STANDARD:
 4.MD.6 Measure angles in whole-number degrees with a protractor. Sketch angles with a
specific measure.
 4.MD.7 Recognize angle measure is additive. Add and subtract to find unknown angles on
a diagram in real world and mathematical problems.
OBJECTIVE (EXPLICIT):
 I can use a protractor to measure angles.
 I can add and subtract angle measures to find an unknown angle.
EVIDENCE OF MASTERY (MEASURABLE):
Chart of recorded information from investigation. Formative assessment problem and
independent worksheet also available.
MATERIALS:
 Pattern blocks (at least 6 of each
color block per group)
 Protractors (1 per group)
 Paper (folded into 4 columns)
 Pencils (1 per group)
ENGAGE (MAKE CONTENT AND LEARNING RELEVANT TO REAL LIFE AND CONNECT TO
STUDENT INTEREST)
DURING
BEFORE
KEY VOCABULARY:
vertex, angle, interior angle, exterior angle
TEACHER WILL:
STUDENT WILL:
 Discuss/review what an angle is and
 Communicate with a partner and
difference between and interior and
share knowledge as a class.
exterior angle on a shape. (Be
 Measure sample angles using a
certain to review the vertex of
protractor and share measurements
angles.)
with a partner and with the class.
 Review how to use a protractor to
measure angles.
 Model folding paper into 4-columns;
label columns: Shape, Diagram,
Sum (of angle Measure at Center
Vertex), Notes/Observations
PRESENT THIS PROBLEM TO THE STUDENT GROUPS TO SOLVE:
Macy is creating a display for the wall of her room using pattern blocks. She places the
blocks in a pattern so there are no gaps or overlaps. What must be true about the sum of
the angle measures at each center vertex point in the pattern?
TEACHER WILL:
STUDENT WILL:
 Have student groups create designs
 Measure the interior angles of each
with a center point, using at least six
pattern block. Record the data on
of each type of pattern block
the group chart.
(hexagon, trapezoid, rhombus,
 Measure the angles that surround a
square, triangle, and diamond (small
rhombus)).



Read the challenge problem on the
board. Remind the students that
their designs must use all of the
pattern blocks they were given and it
must consist of at least one center
vertex.
Monitor groups, checking for designs
that use all pattern block pieces and
include at least one center vertex
point.


center vertex point, add the angle
measures. Record the data on the
group chart.
Create a design to fit the challenge
problem.
Measure angles around one of the
center vertex points; add the angle
measures, and record data on chart.
Discuss as a group the observations
and solutions discovered.
AFTER
CO-TEACHING STRATEGY IF APPLICABLE
TEACHER WILL:
 Have students do a quick gallery
walk to see the designs made by
each group.
 Ask students to communicate their
observations and results to the
class.
Possible Formative Assessment:
 Have students try the following
problem:
What is the measure of the angle X?
A. 30 B. 60 C. 90 D. 120
90
120
X
60
CO-TEACHING STRATEGY IF APPLICABLE
STUDENT WILL:
 Share the group designs,
measurements, sums, and
discoveries.
 Complete formative assessment.