Q3, W8: March 15-18 Geometry

TeacherKristin Andreason
Subject AreaGeometry Honors
Grade Level8
Week #March 15-18
Unit of InstructionUnit 6: Two-Dimensional Measurements
Standard(s) Taught

MAFS.912.G-GMD.1.1:  Give an informal argument for the formulas for the circumference of a circle, area of a circle, volume of a cylinder, pyramid, and cone. (Use dissection arguments, Cavalieri’s principle, and informal limit arguments.)


Learning Targets and Learning Criteria
  • define regular polygons.
  • inscribe a regular polygon in a circle and break it into many congruent triangles to find its area.
  • explain and use the dissection method on regular polygons to generate an area formula for regular polygons A = ½ × apothem × perimeter (A = aP).
  • calculate the area of a regular polygon A = ½ × apothem × perimeter   (A = ½aP).
  • use pictures to explain that a regular polygon with many sides is nearly a circle, its perimeter is nearly the circumference of a circle, and that its apothem is nearly the radius of a circle.
  • substitute the “nearly” values of a many sided regular polygon into   A = ½ × apothem × perimeter (A = ½aP) to show that the formula for the area of a circle is A = LaTeX: \piπr2.
Classroom Activities


  1. Students will log onto the Zoom session.
  2. Students will take the Summative on Quadrilaterals.
  3. We will watch a video showing how we get the formula for area of a circle.
  4. I will give students notes on Regular Polygons.
  5. Students will take notes on area of triangles, squares, and hexagons.
  6. Students will create a foldable on Area of Regular Polygons with practice examples.


  1. Students will log onto the Zoom session.
  2. Students will work on a scavenger hunt on Area of Regular Polygons.


  1. Students will log onto the Zoom session.
  2. Students will finish scavenger hunt.
  3. Students can work on other missing assignments when they finish.
Assignments Due
  • Quadrilaterals Summative must be taken by Thursday (will be given in class on Monday/Tuesday).
  • Scavenger hunt on Area of Regular Polygons due on February 27/28.
Additional Resources

All IEP and ESOL accommodations are provided daily.