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°|
Play with 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
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|