Bucknell University – UBD Lesson Plan

Areas of Circles and Sectors

Teacher_Nathaniel Nauman__________ Grade__9th and 10th____________

Date_Feb. 28, 2013__________________	Subject__Geometry____________

Stage 1- Desired Results
Established Goals: G G.2.2.2.2 - Find the measurement of a missing length, given the perimeter, circumference, or area.
Understandings: U Students will understand… how to calculate the area of a circle how to calculate the area of a sector in a circle why the area of a circle and the area of a sector in a circle are calculated the way that they are calculated	Essential Questions: Q What is the area of a circle and a sector in a circle? How are these areas calculated? How can this information be applied in the real world?
Student will know… K the area formula for the area of a circle the area formula for the area of a sector in a circle	Student will be able to… S calculate the area of a circle when given the diameter or radius, or vice versa calculate the area of a sector in a circle when given the diameter or radius and the measure of the arc on the circle, or the diameter or radius when given the area of a sector
Stage 2- Assessment Evidence
Performance Tasks: T Calculate the area of a pizza and the area of several slices of pizza after some of the pizza has been eaten.	Other Evidence: OE Focus question, practice problems throughout the lesson, various questions and homework problems.
Self-Assessments	Other Evidence, Summarized
Stage 3 Learning Plan
Learning Activities: L Start lesson with a focus question projected onto the SmartBoard which requires students to calculate the radius and diameter of a circle when given its diameter. After confirming that everyone understands how to solve this problem, begin the actual lesson by moving to the next slide where students will be introduced to how the area of a circle is calculated through discussion. Once this concept is introduced, move on to a couple of practice problems which asks students to find the area of a circle when given the radius, or to find the diameter of the circle when given its area. Once everyone is finished solving these problems and everyone understands how to solve these problems, move on to the next slide that has an application problem that asks students to calculate the area of a pizza when given the radius of the pizza pan that it is going to be made in. After this application problem is solved and understood, move to the next slide where students will be asked to explain what a sector of a circle actually is. After hearing students suggestions, provide an explanation of what a sector of a circle is and then move on to the next slide. On this slide students will be given the equation for how to calculate the area of a sector of a circle. Give students a good explanation as to why this equation allows people to calculate the area of a sector and then move on to the next slide. On this slide work through two practice problems involving the area of a sector of a circle, either as what needs to be calculated or as one of the pieces of information provided. Finally, move on to the last slide where students will be asked to calculate the area of several slices of pizza after some of the pizza has already been eaten. If time remains, then hand out homework and ask students to start working on the problems. Extension: Cut a paper into a circle and use it to explain area of a circle in terms of its radius, if necessary, or area of a sector by cutting a piece out of the circle and explaining using what the students know about area of a circle and angle measures in a circle. Resources: White Board, Markers, White Board Erasers, SmartBoard, Projector, PowerPoint Slides, paper, scissors and the homework assignment papers.