5.10 Perimeter and Area
Triangles and Parallelograms
I.SectionObjectives
- Understand the basic concepts of the meaning of area.
- Use formulas to find the area of specific types of polygons.
II.ProblemSolvingActivity-FlooringDilemma
- Here is the problem.
- “Ron is working for a flooring company for the summer. He is assigned the task of figuring out the area of a
strangely shaped room at the library. Here is a diagram of the room that Ron needs to measure.” - Figure 10.01.01
- “Ron thinks that the room looks like two rectangles and one triangle. He has some of the measurements from
his diagram, but needs to figure out some of the other measurements. Is Ron correct? Can the room be divided
into two rectangles and a triangle? What are the missing measurements? What is the area of the room?” - Students will work in pairs to figure out these answers.
- Here are the solutions.
- The length ofxis 8 feet because 12− 4 = 8.
- The area of the first rectangle is 6× 12 =72 feet.
- The area of the second rectangle is 8× 8 =64 feet.
- The area of the triangle is=^12 ( 6 )( 6 ) =18 feet
- Total area= 72 + 64 + 18 =154 feet
III.MeetingObjectives
- Students will understand the basic concepts of the meaning of area.
- Students will use formulas to find the area of specific types of polygons.
- Students will use this understanding in problem solving.
IV.NotesonAssessment
- Be sure that the students answered all of the questions in the problem.
- Are the measurements accurate?
- Did they divide the figure into two rectangles and a triangle?
- Did they find a different variation that works?
- Check all work and offer correction/feedback when necessary.
Trapezoids, Rhombi and Kites
I.SectionObjectives
5.10. Perimeter and Area