- Janine will plant approximately 69 feet.
III.MeetingObjectives
- Students will calculate the circumference of a circle.
- Students will calculate the length of an arc of a circle.
- Students will use what they have learned in problem solving.
IV.NotesonAssessment
- Check student work for accuracy.
- Have the students correctly figured the circumference?
- Have the students correctly figured the arc length?
- Is the answer clearly labeled?
- Offer support/correction when needed.
Circles and Sectors
I.SectionObjectives
- Calculate the area of a circle.
- Calculate the area of a sector.
- Expand understanding of the limit concept.
II.ProblemSolvingActivity-CircleShading
- Students will use what they have learned about area and circles to figure out the area of the shaded region of
the figure. - Figure 10.04.01
- Here is the problem:
- “Use what you have learned about circles and area to find the area of the shaded region of the figure. Show all
of your work in your answer.” - Solution:
- The solution to this problem has two parts.
- First, students need to figure out the area of the circle. Since the length of the side of the square is ten inches,
that is also the diameter of the circle since the circle fills almost the entire square. Therefore, the radius is five
inches. - A=πr^2
- A= ( 3. 14 )( 25 )
- A= 78 .5 in^2
- Next, the students need to find the area of the square.
- A=s^2
- A= 102
- A=100 in^2
- Now since the shaded region is what we are looking to find, we can subtract the area of the circle from the
area of the square, and the remaining inches will indicate the shaded region. - 100− 78. 5 = 21 .5 inches
III.MeetingObjectives
Chapter 5. Geometry TE - Problem Solving