## Rectangle -Geometry Formulas

### Rectangle

A rectangle is a 2-dimensional shape/polygon with four sides, four vertices, and four right angles. The two opposite sides in the rectangle are equal and parallel to each other. ### Area of Rectangle:

The area of a rectangle is the space covered by the shape. Alternatively, the space within the perimeter of the rectangle is the area of a rectangle.

Area = l × b

### Example:

A rectangle is 5 m wide and 3 m high, what is its Area?

Area = 5 m × 3 m

= 15 m2

### Perimeter of a Rectangle:

The Perimeter is the distance around the edges.

Perimeter = 2(l+b)

### Example:

A rectangle is 12 cm long and 5 cm tall, what is its Perimeter?

### Solution:

Perimeter = 2 × (12 cm + 5 cm)

= 2 × 17 cm

= 34 cm

### Diagonals of a Rectangle:

Diagonal “d” = √(a2 + b2)

### Example:

A rectangle is 12 cm wide, and 5 cm tall, what is the length of a diagonal?

D = √(122 + 52)

= √(144 + 25)

= √169

= 13 cm

### Properties Of Rectangle:

• A rectangle is a quadrilateral with four equal internal angles.
• Each internal angle of a rectangle measures 90°.
• As the opposite angles of a rectangle are equal, a rectangle is also a parallelogram.
• The opposite sides of a rectangle are equal and parallel.