Lesson: Perimeter

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Lesson Objective

Students will apply the formula for calculating perimeter to determine the perimeter of geometric figures.

Lesson Plan

Prep:
Teacher must tape sections of the floor into squares and rectangles.

Make sure, if possible each block on the floor can be measured accurately with a 12 inch ruler.

Engagement (Warm- Up) 5 min.:
List the properties of Sqaures and rectangles.

The opposite sides are equal/ squares  have 4 equal sides.

Exploration (Notes) 10 min.:
Perimeter is the total distance around a figure; the sum off all the sides.
Square: 4 x s
Rectangle: 2L + 2W
Polygons: Add the length of all the sides

Explanation (Instructional) 30 min.:
Teacher will display a square that has a length of 2in.
(Squares have 4 equal side so we can add the 2 four times)
P= 2 in. + 2in. + 2in. + 2 in. or 4 X 2in.
P= 8in.

Teacher will display a rectangle that has a length of 5 ft. and a width of 10 feet.

Teacher can ask the students about the formula for rectangles and why it differs from squares, referring back to the warm up. Based on the formula, what should we do to find the perimeter of this rectangle?

Several students can share their method. Once a couple of students have shared, teacher can check the work by applying the formula.

P= 2(5ft.) + 2(10ft.) or 5ft. + 5ft. + 10ft. + 10ft.
P= 30 ft.

Now students must break into groups and try to find the perimeter of each of the figures that is taped down to the floor.

Teacher will allow each group 5 minutes at each square rotating the groups so that each has equal time to measure.

Once the time is up, each group will present their findings on a different sqaure.
Teacher will give confirmation of correct answers.

Elaboration (Independent) 15 min.:

Homework: Perimeter WKST

Evaluation (Closing) 5 min.:
Exit ticket:
What is the perimeter if a rectangle has a length of 24.5cm and a width of 17.5 cm?