# Q3, W8: March 15-18 Geometry Teacher Kristin Andreason Geometry Honors 8 March 15-18 Unit 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 = πr2.
Classroom Activities

Monday/Tuesday:

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.

Wednesday:

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

Thursday:

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.