Learn and know what is a perimeter and how to find it for a rectangle. All the school going students should know about this concept. Perimeter and areas are a very important concept.
Do you know what is a perimeter? A Perimeter is nothing but the sum of all the sides of the given diagram. Now in this case i.e. for a rectangle sum of all the sides gives the perimeter.
The Formula for finding the perimeter of rectangle:
Let us consider a rectangle PQRS with length as “L “units and breadth as “B” units.
Therefore, the perimeter of rectangle PQRS is = 2 (L + B) units.
Proof for the perimeter of rectangle formula:
We know that in a rectangle opposite sides are always equal in length.
PQ = RS = L units
In the same way, QR and PS are equal in length.
QR = PS = B units
Perimeter of rectangle
= sum of all its sides
= PQ + QR + RS + SP
= L + B + L + B
= 2L + 2B
= 2 ( L + B)
Therefore, perimeter of rectangle is also defined as twice the sum of its length and breadth.
*What is the perimeter of rectangle whose length is 5 cm and breadth is 17 cm.
We know that P = 2(L + B)
= 2 (5 + 17)
= 2 (22)
= 44 cm.
*Find the length of the rectangle whose perimeter is 40 cm and breadth is 10cm.
Breadth = 10 cm
Perimeter = 40 cm
We know that
P = 2(L + B)
40 = 2 (L + 10)
40/2 = L + 10
20 = L + 10
20 – 10 = L
10 = L
Therefore, length of rectangle is 10 cm.