Unit 7: Circles

Unit seven is about circles. Students extend their thinking about the Pythagorean theorem and coordinate distance to write the equation of a circle given the center and radius, and graph a circle given its equation. Students examine how central, inscribed and circumscribed angles relate to chords, radii, and arcs of the circles. The idea of radian measure is introduced through the idea that all circles are similar. Throughout the unit, students use constructions to make visual sense of the parts of a circle (radius, chords, etc) and use relationships to solve problems. This unit is a nice culmination of the year and can be used to review concepts from Units 1 through 6 as they are related to circle relationships.

Time frame:
4 weeks
Essential Questions: 
  • How are circles described?
  • How are circular relationships used?
  • How do circles define the relationships among segments, angles, and arcs?
Overall Unit Flow:
Initial Task Developmental Lessons Closure & Assessment
1 lesson 3 weeks (approximately 1 week per big idea) 1 week