# Rectangle

A rectangle is a four-sided flat shape where every angle is a right angle (90°).

 means "right angle" and show equal sides
 Each internal angle is 90° Opposite sides are parallel and of equal length (so it is a Parallelogram).

Play with a rectangle:

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## Area of a Rectangle

 The Area is the width times the height: Area = w × h

### Example: A rectangle is 6 m wide and 3 m high, what is its Area?

Area = 6 m × 3 m = 18 m2

## Perimeter of a Rectangle

The Perimeter is the distance around the edges.

 The Perimeter is 2 times the (width + height): Perimeter = 2(w+h)

### Example: A rectangle has a width of 12 cm, and a height of 5 cm, what is its Perimeter?

Perimeter = 2 × (12 cm + 5 cm) = 2 × 17 cm = 34 cm

## Diagonals of a Rectangle

 A rectangle has two diagonals, they are equal in length and intersect in the middle.
 The Diagonal is the square root of (width squared + height squared): Diagonal "d" = √(w2 + h2)

### Example: A rectangle has a width of 12 cm, and a height of 5 cm, what is the length of a diagonal?

 Diagonal Length = √(52 + 122) = √(25 + 144) = √169 = 13 cm