G4 L13-6 Solve Perimeter and Area Problems (1)

Lesson 13-6

Solve Perimeter & Area Problems

Lesson Objective

• Find the unknown length or width of a rectangle using the known area or perimeter.

Essential Question

How can you use perimeter and area to solve problems?

Open Ended

What are the length and width of your book?

Open Ended

What would you find if you add them then multiply the sum by 2?

Open Ended

What would you find if you multiply the height by the width?

https://www.youtube.com/watch?v=rSVMrPu0__U

Perimeter Vs Area

• The perimeter of a figure is the distance around the figure.

• To find the perimeter of a rectangle, use the formula

  P = 2l + 2w or 2(l + w)

• The area of a figure is the number of square units needed to cover the figure.

• To find the area of a rectangle, use the formula A = l x w

Multiple Choice

A rectangular birthday cake (shown above) measures 8 inches by 12 inches. What is the perimeter of the cake?

• 32 in

• 40 in

• 20 in

• 96 in

Multiple Choice

A rectangular birthday cake (shown above) measures 8 inches by 12 inches. What is the area of the cake?

• 32 in2

• 40 in2

• 20 in2

• 96 in2

Fill in the Blanks

Challenging Question - A rectangle has a width of 14 cm & a perimeter equal to 80 cm. What is its height?

https://www.youtube.com/watch?v=UyLTqfbhicw

Fill in the Blanks

Challenging Question - A rectangle has a width of 9 feet and an area equal to 36 ft2. What is the measure of the missing length?

https://www.youtube.com/watch?v=Z4zzMCAAoxU&t=16s

How can you use perimeter and area to solve problems?

• The formulas for perimeter & area of rectangle can be applied to determine the length or the width of a rectangle when given the area & one side or the perimeter & one side.

Open Ended

A rectangle has a perimeter of 36cm. What could the area of this shape be?

Open Ended

TODAY’S LESSON TWEET

What did you learn today?

What did you find challenging?