Texas Essential Knowledge and Skills (TEKS):
5.4.H
represent and solve problems related to perimeter and/or area and related to volume.
Florida - Benchmarks for Excellent Student Thinking:
MA.5.GR.2.1
Find the perimeter and area of a rectangle with fractional or decimal side lengths using visual models and formulas
5th Grade Math - Perimeter & Area Lesson
Perimeter is the distance around an object.
Perimeter of Rectangle
Perimeter = length + width + length + width
OR
Perimeter = 2 × length + 2 × width
Example:
Use the given information to set up an equation and solve for the width. For the equation, use the sum of the sides, or use two times length plus two times width.
Perimeter
=
length
+
length
+
width
+
width
60 feet
=
20 feet
+
20 feet
+
width
+
width
60 feet
=
40 feet
+
width
+
width
60 feet
=
40 feet
+
10 feet
+
10 feet
OR
Perimeter
=
(2 × length)
+
(2 × width)
60 feet
=
(2 × 20 feet)
+
(2 × width)
60 feet
=
40 feet
+
(2 × width)
60 feet
=
40 feet
+
20 feet
60 feet
=
40 feet
+
(2 × 10 feet)
The width of the rectangle is 10 feet.
Example:
First, find the sum of the side lengths that are given.
5 feet + 10 feet + 5 feet = 20 feet
Then, subtract the sum from the perimeter.
24 feet - 20 feet = 4 feet
The length of the missing side is 4 feet.
Area of Rectangle
Area = length × width
Example:
Use the formula for the area of a rectangle.
Area
=
length × width
=
10 feet × 4 feet
=
40 square feet
The area of the rectangle is 40 square feet.
Example:
Use the given information to set up an equation and solve for the width.