# How do you find the diagonal of a rectangle whos length and width of a rectangle are 8 cm and 6.5 cm?

Oct 15, 2015

The diagonal is $10.3 c m$

#### Explanation:

As per the property of rectangles the length and breadth (width) are at right angles(perpendicular) to each other.

Keeping this property in mind, the diagonal can be found by applying the Pythagoras theorem , as the length , breadth and diagonal together form a right angled triangle(diagonal being the hypotenuse).

Let the length $= A B = 8 c m$

breadth $= B C = 6.5 c m$

Diagonal $= A C$

Applying the Pythagoras theorem :

$A {C}^{2} = A {B}^{2} + B {C}^{2}$

$A {C}^{2} = {\left(8\right)}^{2} + {\left(6.5\right)}^{2}$

$= 64 + 42.25$

$= 106.25$

$A C = \sqrt{106.25}$

AC color(blue)(approx10.30cm

The diagonal is $10.3 c m$