ACT Math
Lesson Plan
Circumference and area
Goals / Objectives
Compute the circumference (C = 2pir = pid) and area (A = pir^2) of a circle from its radius or diameter, converting a diameter to a radius where the formula needs it
Express answers in terms of pi or as decimal approximations, as the problem requires
Solve for a missing radius or diameter given the circumference or area of a circle
Compute the area and perimeter of semicircles and quarter circles, and the area of shaded regions and annuli, by combining circle formulas with other geometric reasoning
Standards
G 507. Compute the area and circumference of circles after identifying necessary information G 405. Use geometric formulas when all necessary information is given G 505. Compute the perimeter of simple composite geometric figures with unknown side lengths G 702. Compute the area of composite geometric figures when planning and/or visualization is required
Academic Vocabulary
Not in our source material
Enrichment
This lesson’s brief has no Differentiation
Accommodations
Not in our source material
Anticipatory Set / Bell Work
Modeling
Check for Understanding
This lesson’s brief has no Formative Assessment or Assessment Ideas
Guided Practice
Independent Practice
Homework
Pacing
This lesson’s brief has no Pacing