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: Stage 1: Lines of Symmetry
Required Preparation
Materials to Gather
Colored pencils, crayons, or markers
Materials to Copy
Blackline Masters
Centimeter Grid Paper - Standard
Centimeter Dot Paper - Standard

Narrative
Each student chooses whether to use dot or grid paper. Each student creates a half of a design and draws a line of symmetry. Students switch paper and complete each other’s designs.


aligns: no