Perimeter of a Rectangle

Rectangles space four-sided polygons. Adhering to are the properties of a rectangle:

(i) every the angles of a rectangle space 90º.

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(ii) Opposite political parties of a rectangle are constantly the very same in size.

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Perimeter the a rectangle

The perimeter the a rectangle is the total length of every the political parties of the rectangle. Hence, us can discover the perimeter by adding all 4 sides that a rectangle.

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Perimeter that the given rectangle is a + b + a + b. Because opposite political parties of a rectangle are always equal, we need to uncover the dimensions of only two political parties to uncover the perimeter the a rectangle.

The perimeter of the over rectangle with sides ‘a units’ and ‘b units’ is:

a + b + a + b = 2a + 2b = 2 (a + b) units.

Hence, the formula for the perimeter that a rectangle = 2 × (sum of adjacent sides)

Examples of detect the perimeter of a rectangle

Example 1. The 2 sides that the rectangle room given. What will certainly be the perimeter of the rectangle?

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Solution: One side of the rectangle is 2 cm and the other side is 5 cm.

We know that, the perimeter that a rectangle = 2 × (sum of surrounding sides)

Therefore, the perimeter the the rectangle = 2 × (5 + 2) = 2 × (7) = 14 cm

Example 2. A rectangle-shaped playground is 20 m long and 13 m wide. Discover its perimeter.

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Solution: One side of the rectangular playground is 20 m and also the various other side is 13 m.

We recognize that, the perimeter that a rectangle = 2 × (sum of nearby sides)

Therefore, the perimeter the the rectangular ground = 2 × (20 + 13) = 2 × (33) = 66 m

Tricky difficulties involving perimeter that rectangles

Type I: once the perimeter and also only among the sides are given.

Example 1. If the perimeter the the offered rectangle is 10 cm and the length of among its political parties is 2 cm. What will be the various other side?

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Solution: The perimeter that the rectangle, with one of the sides equal to 2 cm, is 10 cm.

Let the lacking side be ‘a’.

We recognize that, the perimeter the a rectangle = 2 × (sum of adjacent sides)

10 = 2 × (2 + a) 5 = (2 + a)

a = 5 - 2 = 3 cm

Type II: finding sides using the properties of a rectangle.

Example 2. In the given rectangle, if a = 4 cm and also d = 3 cm. Find b and c.

Solution: We understand that next a = 4 cm and side d = 3 cm.

To uncover side b and c, we usage the property that the opposite political parties of a rectangle are constantly the exact same in size.

Hence, a = c = 4 cm and d = b = 3 cm.

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fun Facts

Many historical buildings have rectangle prefer shapes in castle e.g. Parthenon in Athens.