standard_description: Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement:
- An angle is measured with reference to a circle with its center at the common endpoint of the rays, by considering the fraction of the circular arc between the points where the two rays intersect the circle. An angle that turns through 1/360 of a circle is called a “one-degree angle,” and can be used to measure angles.
- An angle that turns through n one-degree angles is said to have an angle measure of n degrees.
problem_activity: Narrative
This warm-up prompts students to carefully analyze and compare representations of patterns. Listen for the language students use to describe and compare the elements of each pattern and give them opportunities to clarify what they mean when they use numbers to describe the patterns (MP6).
Launch
Groups of 2
Display image.
“Pick one that doesn’t belong. Be ready to share why it doesn’t belong.”
1 minute: quiet think time
Activity
“Discuss your thinking with your partner.”
2–3 minutes: partner discussion
Share and record responses.
Student Facing
Which one doesn’t belong?
A
[IMG]
B
[IMG]
C
[IMG]
D
[IMG]
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
“What features of the diagrams did you look at when you tried to find which one doesn’t belong?” (Sample response: the number of small squares in each shape)
If time permits, ask students to think about which one doesn’t belong if they pay attention to the number of rows or the perimeter rather than the number of squares.


aligns: no