The perimeter of the rectangle is the sum of the length of all its sides.
For example, if the sides of the rectangle are A,B,CandD, its perimeter will be AB+BC+CD+DA. It is customary to indicate the perimeter by the letter P.
Important to remember!
Rectangles have two pairs of opposite, parallel and equal sides. Therefore, it is enough to know the length of two coincident sides to calculate their perimeter.
Since in a rectangle every pair of opposite sides are equal to each other, we can claim that:
EF=BC=AD=5
FC=EB=3
Now we can calculate side AB:
8+3=11
Since AB and CD are equal to each other, side CD is also equal to 11
Let's calculate the perimeter of the rectangle:
11+5+11+5=22+10=32
Answer
32
Exercise #12
ABCD, EFCD, and ABFE are all rectangles.
Calculate the perimeter of rectangle ABCD.
Video Solution
Step-by-Step Solution
Since in a rectangle every pair of opposite sides are equal to each other, we can claim that:
AE=BF=5
AB=CD=9
Now we can calculate side BC:
5+3=8
Since side BC is equal to side AD, it is also equal to 8
Let's calculate the perimeter of rectangle ABCD:
9+8+9+8=18+16=34
Answer
34
Exercise #13
Look at the rectangle below.
Side AB is 4.8 cm long and side AD has a length of 12 cm.
What is the perimeter of the rectangle?
Video Solution
Step-by-Step Solution
In the drawing, we have a rectangle, although it is not placed in its standard form and is slightly rotated, but this does not affect that it is a rectangle, and it still has all the properties of a rectangle.
The perimeter of a rectangle is the sum of all its sides, that is, to find the perimeter of the rectangle we will have to add the lengths of all the sides. We also know that in a rectangle the opposite sides are equal. Therefore, we can use the existing sides to complete the missing lengths.
4.8+4.8+12+12 = 33.6 cm
Answer
33.6 cm
Exercise #14
Given the square,
What is its perimeter?
Video Solution
Step-by-Step Solution
Since in a square all sides are equal to each other, all sides are equal to 8 cm
Now we can calculate the perimeter:
8×4=32
Answer
32
Exercise #15
What is the perimeter of the given rectangle ABCD?
Video Solution
Step-by-Step Solution
According to the data let's consider:
CF=DE=3
AE=BF=5
Now we can calculate BC:
5+3=8
AD=BC=8
Next we pay attention to any additional information and it seems that:
GB=HC=4
DH=AG=7
Hence we can calculate AB:
7+4=11
AB=DC=11
Lastly we can calculate the perimeter of the rectangle ABCD: