Calculations of central angles are attempted, but many errors are made. Assistance is necessary. Able to estimate the size of angles within a reasonable range. Use mathematical language to describe geometric ideas. Calculations of the central angle are made with little error.
Works independently needs little assistance.
Understands and demonstrates congruence of figures by measuring angles and sides matching corresponding parts. Able to use mathematical terms and calculate the central angle with no errors. Assistance is necessary. Some circle graphs are incomplete or inaccurately drawn. Assistance is necessary.